ANNUAL REPORT2011 - 2012

Raman Research InstituteBangalore

Sir C V Raman

C O N T E N T SIntrIntrIntrIntrIntroductionoductionoductionoductionoduction From the Director 6

AAAAAbout the Institutbout the Institutbout the Institutbout the Institutbout the Instituteeeee History 7RRI at a Glance 10

Areas of RAreas of RAreas of RAreas of RAreas of Researesearesearesearesearchchchchch

Astronomy and AstrophysicsOverview 15

Ongoing Research 20

Light and Matter PhysicsOverview 41

Ongoing Research 44

Soft Condensed MatterOverview 53

Ongoing Research 56

Theoretical PhysicsOverview 73

Ongoing Research 76

FFFFFacilitiesacilitiesacilitiesacilitiesacilities 84

AAAAAcademic Prcademic Prcademic Prcademic Prcademic Programsogramsogramsogramsograms 89

PPPPPeople at RRIeople at RRIeople at RRIeople at RRIeople at RRI 91

PublicationsPublicationsPublicationsPublicationsPublications 104

Other AOther AOther AOther AOther Activitiesctivitiesctivitiesctivitiesctivities 105

AppendicesAppendicesAppendicesAppendicesAppendices 111

StatStatStatStatStatement of Aement of Aement of Aement of Aement of Accountsccountsccountsccountsccounts 169

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D I R E C T O Rfrom the

The annual report of the Raman ResearchInstitute for the year 2011-12 is a summary ofthe research and academic activities of theinstitute during the year.

The annual report, as in the past, presentssynopses of the ongoing knowledge creationactivities in the different research groups, manyof which have outcomes in the form ofpublications in refereed scientific journals. Theinstitute considers the transmission ofknowledge an important activity; this alsoincludes the guidance of students for theconferment of PhD degrees as part of the PhDprogramme of the Institute, as well as the activeVisiting Students Programme under which anumber of students from all over the countryvisit the institute for stays ranging from a fewweeks to several months and participate in themany research activities of RRI. It alsocontinued holding schools in where studentsand young scientists from across the countryparticipated.

Communications of the ongoing research andalso a sharing of knowledge of current research– in professional talks given by members of theInstitute in conferences and in externalinstitutions as well as journal review talks at theinstitute – is another aspect of our knowledgediffusion. A cultural function of a premierresearch institute is the upholding andpromotion of academic traditions and this

naturally includes the conduct of specialisedseminars on technical topics targeted atspecialised audiences as well as colloquia in awider range of topics that are delivered in astyle that strives to make current advancesintelligible to a wider community.

Outreach activities include facilitating theinvolvement of students of a local school tohelp collect astronomical data as part of aninternational project, and helping a schoollocated in hinterland to reinstall the dome at itscampus to start an optical telescope, as well aswritings intended for a lay and discerningaudience and the delivery of motivational talksat educational institutions.

Included in this report are lists of publicationsin refereed journals, conference proceedings aswell as in monographs, books and in popularperiodicals, PhD degrees awarded during theperiod 01 April 2011 to 31 March 2012 as wellas seminars and review meetings focused oncurrent research, which were held at theinstitute. The report also lists the scientists whohave visited the institute from within India andfrom overseas during the period.

BangaloreAugust 31, 2012

Ravi SubrahmanyanDirector

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Before being immersed in the current

exciting research activities conducted at

the Raman Research Institute (RRI), take a

few moments to read about its history. In

between the collection of historical facts

you’ll discover a story about the power of

basic human curiosity – the invisible

foundation on which RRI was built and

managed by its founder Sir CV Raman and

subsequently by his successors.

H I S T O R Ya bit of

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In 1934, while still the director of the IndianInstitute of Science (IISc), Raman started theIndian Academy of Sciences and attracted

most of the best young scientists of that time,who published their work in world renownedjournals of physics and chemistry. That sameyear, the Maharajah of Mysore gifted to theAcademy 11 acres of land in the north side ofBangalore. A few years later, Raman proposedthat an independent research institute be builton those premises and an agreement with theAcademy was signed. The new centre wasnamed after its founder – Raman ResearchInstitute.

Raman embarked on a number of long journeysthroughout the country to raise funds for thenew institute. In 1943, the collected sum, alongwith his personal savings, was allotted for theconstruction of the first building. Its initialcompletion coincided with the retirement of SirCV Raman from IISc in 1948 and in thebeginning of 1949 he shifted all his activitiesthere.

From the very first moment of its foundationRaman undertook the management of his newinstitute with immense vigour and enthusiasm.He not only designed the main building with thehelp of an architect, but also took great interestin the arrangement of the whole premises. Heplanted trees, decorative bushes and flowersturning the barren land around into a beautifulgarden. A walk in that garden was anindispensable part of his daily life. The initialstaff in the new institute consisted of fourpeople including Raman himself. The lack ofelectricity during the first two years didn’t affectRaman’s thirst for knowledge andunderstanding the wonders of Nature. Greatscientific work was carried out during theseyears using a few lenses and a manuallyoperated heliostat. In order to support his staffand expand scientific activities at RRI, Raman,who was unwilling to take money from thegovernment, started a couple of chemicalindustries along with one of his formerstudents. He used the profit to pay his staff and

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equip his laboratories. In the years to come, theinstitute kept expanding – soon there was anew library, a few other buildings and amuseum holding Raman’s personal collection ofgems, crystals and minerals. Until his death inNovember 1970, Raman kept working tirelesslyfor the development and growth of the RamanResearch Institute.

After his death, the Academy created a publiccharitable trust: the Raman Research InstituteTrust. The lands, buildings, deposits, securities,bank deposits, moneys, laboratories,instruments, and all other movable andimmovable properties held by the Academy forthe Raman Research Institute were transferredto the RRI Trust. The foremost function of theRRI Trust was to maintain, conduct and sustainthe Raman Research Institute.

In 1972, the institute started receiving fundsfrom the Department of Science and Technologyof the Government of India which, since then,has been its main funding source. The same

year, Venkatraman Radhakrishnan was invitedto be the Director of RRI. A renowned scientisthimself, Radhakrishnan not only fulfilled CVRaman’s desire to build an observatory at RRIbut formed a strong group in Astronomy andAstrophysics whose research work today isregarded highly worldwide. Until the mid 90s,the two main areas of research were LiquidCrystals and Astronomy and Astrophysics. Theconstant growth of RRI and the expansion of theresearch interests of its members led to theestablishment of two new groups – TheoreticalPhysics and Light and Matter Physics. TheLiquid Crystal group was renamed SoftCondensed Matter which conveys moreaccurately the diverse research activities of itsmembers.

Today, RRI research faculty, scientific staff andstudents conduct active research in the abovementioned four scientific fields inspired by theexample of the founder – Sir CV Raman.

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G L A N C Eat a

M i s s i o n

RRI is engaged in fundamental research in the areas of Astronomy,Astrophysics, Light and Matter Physics, Soft Condensed Matter andTheoretical Physics as a part of the global endeavour to increase humanknowledge and understanding of the world.

D i r e c t o r

The current director of the Raman Research Institute is Ravi Subrahmanyan.

O r g a n i s a t i o n

RRI is an autonomous research institute. The supreme body of RRI is theRRI Trust. The director is the chief executive and academic officer. TheGoverning Council is the executive body responsible for the administrationand management of the Raman Research Institute. The Finance Committeehelps the Council with financial matters.

L o c a t i o n

RRI is located on a 20-acre plot in the north of Bangalore City, the IT capitalof India. It offers a quiet refuge from the bustling megapolis as well as anatural environment that is highly conducive to creative scientific work.

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R e s e a r c hA r e a sAstronomy and Astrophysics

Light and Matter Physics

Soft Condensed Matter

Theoretical Physics

F a c i l i t i e s

1. LABORATORIES:

RAL/Electronics Lab

X-ray Astronomy Lab

Quantum Optics LabLaser Cooling and Light Propagation LabQuantum Interactions LabNon Linear Optics LabLaser-induced Plasma Lab

Chemistry LabPhysical Measurements LabLiquid Crystal Display LabRheology and Light Scattering LabX-Ray Diffraction LabBiophysics LabElectrochemistry and Surface Science Lab

MECHANICAL ENGINEERINGMechanical WorkshopGlass Blowing Facility

2. LIBRARY

3. COMPUTER FACILITIES

E d u c a t i o n

RRI offers the following academicprogrammes:

– PhD Programme

– Post Doctoral Fellowship Programme

– Visiting Student Programme

F u n d i n g

RRI is funded by the Department of Scienceand Technology, Government of India.

F a c u l t y ,S t a f f &S t u d e n t sResearch Faculty 46

Scientific/Technical 49

Administrative 28

PhD Students 56

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O r g a n i s a t i o n

A&A

TP

SCM

LAMP

Administration

Library

Head, Research Facilities

Accounts

Purchase

Stores

Security

Horticulture

Canteen

Public Relations

Buildings

Maintenance

Electrical

Waste Management

Subramanya

Ramamurthy

B Murthy

Ganapathy

R Sasidharan

Srihari

Ram

Suresh

R Sasidharan

AS Rao

R Sasidharan

Udaya Shankar

Sanjib Sabhapandit

Sandeep Kumar

Sadiq Rangwala

K KrishnamarajuK Raghunatha

B Meera

Hema Ramachandran

Computer

Workshops

RAL/Electronics Lab

Nanda Kumar

Ateequlla

RAL CoordinationComm Chairperson - Srivani

GBD Field StationAswathappa

Director

Ravi Subrahmanyam(Chairman)

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Journal Club Supurna Sinha

Colloquia Joseph Samuel, Pramod Pullarkat, Sadiq Rangwala

Hostel Warden Krishnama Raju, Arun Roy

Admissions Coordinator Arun Roy

SAAC Madan Rao

In-House Meeting PhD students

JAP Rep of RRI Shiv Sethi

Complaints Committee Srivani (Chairperson), Marisa, Vrinda, K Raghunatha,Madan Rao

Chairpersons of PhD Abhishek Dhar, Biswajit PaulInterview Committees

Overseas Travel Committee Sandeep Kumar (Chairman), Udaya Shankar, Madan Rao

Evaluation Committee Joseph Samuel, Hema Ramachandran, Biman Nath,Abhishek Dhar, VA Raghunathan

Senior Management Team Ravi Subrahmanyan, TN Ruckmongathan, Udaya Shankar,Joseph Samuel, K Krishnamaraju, K Raghunatha

Coordinator of Supurna SinhaVisiting Students Programme

Coordinator of Abhishek DharSummer Students Programme

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ASTRONOMYAND

ASTROPHYSICS

ASTRONOMYAND

ASTROPHYSICS

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The Astronomy and Astrophysics (A&A)

group at RRI comprises nearly 20

motivated researchers who study the

universe from its creation to its present

state. The main areas of research

include theoretical astrophysics,

observational astronomy, astronomical

instrumentation and signal processing.

offer new directions of study. Such studies havebeen the basis of our collective knowledge ofthe universe.

Telescopes have been used since the 17thcentury to study the universe. Today’s highlysophisticated telescopes allow scientists tostudy celestial bodies in different frequencybands of the electromagnetic spectrum, andanswer questions about the universe and itscreation. RRI’s astronomical instrumentationengineers are involved in the construction andoperation of such telescopes around the world.

The following pages summarise the major areasof research for the A&A group as well as eachmember’s individual work during the last year.This section will give the reader a more detailedand technical description of the members’respective research activities.

Theoretical astrophysics concentrates on thedevelopment of analytical models andcomputational numerical simulations that try todescribe the dynamics, physical properties andunderlying phenomena of celestial objects(such as stars, planets, galaxies and interstellarmedium, among others) as well as answerfundamental questions about the formation andevolution of the universe.

Observational astronomers use numeroustelescopes built across the globe to study theradiation from space covering the entireelectromagnetic spectrum – which ranges fromlow frequency (long wavelength) radio waves tovery high frequency (short wavelength andextremely energetic) gamma rays. Theseobservations form part of the information that isused to test existing theoretical models and

O v e r v i e w

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ASTROPHYSICSDevelopment of Cosmological Models:Cosmology is concerned with developing andtesting physical models that try to explain theformation and evolution of the universe.Researchers at RRI are working on developingsuch models that describe radiation from theEpoch of Reionisation (EoR). EoR refers to theperiod in the early history of the universe duringwhich the emergence of the first luminoussources (such as stars and galaxies) ionised thepredominantly neutral intergalactic medium.These models can provide importantinformation about the process of structureformation in the universe and answer questionsas to whether such radiation can be detectedwith existing telescopes.

Magnetohydrodynamic (MHD) Turbulence:Turbulence in electrically conducting fluids is ararely observed phenomenon here on Earth.However, in galaxies, clusters of galaxies andthe interstellar medium, where matter isionised, it is a widespread phenomenon.Researchers at RRI are actively working towardsthe development of a comprehensivetheoretical formulation of MHD turbulence.

Dynamo Theory: The astrophysics community atRRI conducts theoretical work to understand theorigins of large magnetic fields around cosmicobjects (stars, planets and galaxies) and theprocesses that sustain them. It is suchmagnetic fields that protect the Earth from thesolar wind of particles that would otherwisedestroy life on our planet.

Gravitational Dynamics: RRI researchers arealso involved in the construction of models thatdescribe the structure of the orbits of cosmicbodies around black holes. One of the ways ofunderstanding gravitational lensing (thegravitational bending of light), which waspredicted by Einstein, is by observing andstudying the orbits of stars close to massiveblack holes.

OBSERVATIONAL ASTRONOMYHalo and Relic Radio Sources: Clusters ofgalaxies are the largest structures of matter inthe universe. An understanding of theirformation, structure and dynamics can bringimportant insights about their evolution. Halosand relics are structures within a galaxy clusterthat emit strong radiation in the radio portion ofthe electromagnetic spectrum. Various modelsexist that attempt to explain the origin of thisradiation. Currently, researchers at RRI compareobservational data from the radiations of radiogalaxies with active galactic nucleus (AGN) haveshown that some are slowly dying out. Howmany such galaxies stay invisible to us becauseof the limitations posed by the sensitivity oftoday’s telescope receivers and what bringsabout the end of AGN are some of the questionsthat concern researchers at RRI.

HI Regions in the Milky Way InterstellarMedium: After the Big Bang, some 13.7 billionyears ago, hydrogen was created in greatquantities in the universe making it the basicbuilding block of stars. The space between starsis filled with neutral hydrogen at extremely lowdensities compared to the air we breathe onEarth. The emissions from these hydrogenregions – called HI regions – carry informationabout the conditions before star formation.Researchers at RRI look at the formation andstructure of such HI regions using observationaldata from various radio telescopes in India andabroad.

Pulsars: The detection of pulsars wasserendipitous. Pulsars are neutron stars thatoriginate in supernovae and spin very fast dueto the conservation of angular momentum andperiodically emit radio waves. Because of theirperiodic emission, pulsars are often called “thelighthouses of the universe”. We can onlyobserve pulsars that beam in the direction ofEarth. Pulsar emissions provide insight abouttheir structure and distance. They are also awonderful experimental platform to test generalrelativity. Today, millisecond pulsars are one of

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the most accurate clocks that have been foundin the universe. RRI continues to conduct activeresearch on pulsars and develop receivers thatcould reveal further details about their nature.

Lifecycle of Radio Galaxies: As radio telescopesbecome increasingly sensitive and of greaterresolution, intricate features and morphologiesof and within radio galaxies can be observed. Aparticular type of galaxy, called restarting radiogalaxies, has captured the interest ofresearchers at RRI. It is believed that activity inthe nucleus of the galaxy had stopped and thenstarted again fresh. Such a scenario wouldexplain the observations made and provide auseful input to our understanding of theevolution and lifecycle of radio galaxies. Whydid the nucleus die, how long was it deadbefore it restarted its activity, what are themechanisms that triggered its rebirth – thoseare some of the questions RRI astronomers aretrying to answer in collaboration with Indian andinternational colleagues.

Radio Galaxy Morphologies: In recent years, X-shaped radio galaxies have caught the interestof the astronomy community, and members ofthe A&A group at RRI are active participants inthis research field. In X-shaped radio galaxies,the typical two lobes are accompanied by twoothers to form a radio galaxy whose lobes looklike the letter X. Two of the lobes are activewhile the other two are dead. Theories competeto explain how the two additional lobes aregenerated. Current observations at RRI areused to test these theories and deepen ourunderstanding of X-shaped radio galaxies.

X-ray binaries: Compact stars (neutron stars andblack holes) create some of the most extremeconditions in the universe and the extremeconditions are best investigated using the highenergy emissions radiated from these compactstars in binary stellar systems. The high energyemission, mostly X-rays, are accessible to theastronomers from a fleet of space X-rayobservatories. Astronomers at RRI use

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observations made with a range of internationalspace observatories to investigate the topics oforbital evolution of binary X-ray stars and orbitalglitches, quasi-periodic oscillations in X-raypulsars with many new discoveries to theircredit, self absorption in X-ray pulsars and dipsin the pulse profiles, cyclotron absorption linesin X-ray pulsars, study of neutron star magneticfield and optical reprocessing of thermonuclearX-ray bursts. The upcoming Indian missionAstrosat and an X-ray polarimeter that is underdevelopment at the Institute will significantlyenhance our effort in study of X-ray binaries.

INSTRUMENTATION – DESIGNAND DEVELOPMENTRRI is involved in the design and developmentof several telescopes across the world. Mostcurrent antenna systems are based on largereflectors with a single or a small number offeeds. The Murchison Widefield Array and LowFrequency Array prototypes have heralded aparadigm shift in the design of next generationof radio telescopes. Science projects like EoRand transients have pushed the interestingrange of frequencies for many next generationradio telescopes to less than a GHz withsignificantly improved sensitivity with largebandwidths and large field of view. This can berealised with a phased array or Aperture Array,where the number of beams depends only onthe available processing power and availablecommunications.

RRI has accumulated expertise in this field withits involvement in the Guaribidanur RadioTelescope, Mauritius Radio Telescope,Murchison Widefield Array and development ofbroadband feed for the Greenbank RadioTelescope. The institute is also working on aprogramme to develop the Aperture Arraytechnology in the frequency range 50 to 1000MHz.

Mauritius Radio TMauritius Radio TMauritius Radio TMauritius Radio TMauritius Radio Telescope (MRelescope (MRelescope (MRelescope (MRelescope (MRT)T)T)T)T): The MRT isa Fourier synthesis array, constructed and

operated collaboratively by RRI, Indian Instituteof Astrophysics and the University of Mauritius.The telescope is situated at Bras d’Eau, in thenorth-east of Mauritius, an island in the IndianOcean. The telescope is a T-shaped non-coplanar array, consisting of a 2,048 m longEast-West (EW) arm and an 880m long Southarm. In the EW arm 1,024 helices are arrangedin 32 groups; in the south arm, 16 trolleys with4 helices each that move on a rail are used forsynthesis. A 512 channel, 2-bit 3-level complexcorrelation receiver is used to measurevisibilities. At least 60 days of observations arerequired for obtaining the visibilities up to880m spacing. After calibration, the visibilitiesare transformed to adjust for the non-coplanarity of the array and to produce animage of the area of the sky under observation.It is used to observe the sky at 151.6 MHz inthe declination range of -70° to -10°. Thescientific objectives of MRT are to produce radiosurveys of the southern sky, observe and studypulsars, solar radio emission, extragalacticradio sources, supernova remnants and steepspectrum sources. New developments in theanalysis of the data have allowed the group tocomplete imaging of an additional steradian ofthe sky covering the declination range -70° <Dec <-10° and the sidereal hour range 00hr to06hr. In the mean time, the institute has beencataloguing extended sources seen in the MRTsurvey.

Gauribidanur Radio TGauribidanur Radio TGauribidanur Radio TGauribidanur Radio TGauribidanur Radio Telescope (GRelescope (GRelescope (GRelescope (GRelescope (GRT)T)T)T)T): Thisdecametre wave radio telescope atGauribidanur (around 100km north ofBangalore) is operated as a collaborationbetween RRI and Indian Institute ofAstrophysics. Operating at 34.5 MHz, it is ameridian-transit instrument with some amountof tracking capability. The telescope consists of1,000 fat dipoles arranged in the form of theletter “T”. The dipole orientation is along theEast-West direction, making the instrumentsensitive to only the East-West component ofthe polarisation. The usable bandwidth is about10 MHz centred at 32 MHz, while the maximum

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available effective collecting area is about18,000 square metres. The array beams aresteered by appropriately phasing theirelements. The beam of the N-S arm can betilted within a declination range -45° to 75°.The beam of the E-W array can be tiltedsimilarly in hour-angle within 10° around themeridian enabling tracking for a minimum of 42minutes. This telescope is used for continuumsurveys of the accessible sky, studies ofsupernova remnants, giant HII regions, as wellas radio emissions from the undisturbed sunand solar bursts. Using the tracking facility,observations of low-frequency radiorecombination lines and emission from manynearby pulsars have been made.

XXXXX-ra-ra-ra-ra-ray Py Py Py Py Polarimeolarimeolarimeolarimeolarimetttttererererer: X-ray polarimetry is anunexplored area of high energy astrophysics.Thus far, there has been only one experimentfor X-ray polarisation measurement and Crabnebula is the only source for which a definitepolarisation measurement exists. RRIastronomers are developing methods ofdetecting polarised X-rays from celestial bodiesand building X-ray instruments that can detectpolarised X-rays. These instruments will belaunched into space and open new eyes tocelestial phenomena. For this, RRI has a fullyequipped lab for the fabrication and testing of

X-ray detectors.The researchersare working onthe developmentof an X-raypolarimetersensitive in theenergy range of5-30 keV; theinstrument willbe launched in tospace incollaborationwith ISRO. Alaboratory modelhas been made

and was tested successfully. The design andfabrication of an engineering model is inprogress. This involves the redesign of the labmodel taking into consideration the differentstandards required for space qualification.

AstrAstrAstrAstrAstrosatosatosatosatosat: This is ISRO’s satellite mission formulti-wavelength astronomy whose majorscientific goals include: broadbandspectroscopic studies of X-ray binaries, AGN,clusters of galaxies and stellar coronae and skysurveys, among others. RRI has been involvedin the development of Large Area X-rayProportional Counter (LAXPC) for X-ray timingand low-resolution spectral studies over a broadenergy band, one of the payloads on Astrosat.LAXPC is designed to have a large photoncollection area, which will enable detailedstudies of high frequency features in X-ray lightcurves of bright and medium intensity point X-ray sources. However, to make use of such highsensitivity for intensity variation studies, it isnecessary to measure, understand, andminimise systematic uncertainties in the timingresponse of LAXPC detectors and processingelectronic units. Researchers at the X-rayastronomy lab in RRI are currently working onthe timing and spectral calibration of theAstrosat-LAXPC instrument and development ofthe data reduction software.

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AAAAAvinash Deshpandevinash Deshpandevinash Deshpandevinash Deshpandevinash Deshpande’s current research areas ofinterest are neutron stars, pulsars andtransients, the galaxy and interstellar medium,and instrumentation and signal processing.

During the year gone by, Deshpande’s researchincluded studies of images of a few hundred OHmaser sources in the star-forming complexW49N, obtained from VLBA observations. Theseshowed significant anisotropy in the sources’shapes, understood to be due to anisotropicscattering in the intervening medium. Themagnitude of anisotropy apparent in the scatter-broadened shapes is similar to that reported inan earlier study by Desai et al, even though theoverall sizes are found to be overestimated inthe latter. Further detailed analysis revealedthat the orientations (position angles) of thesource image ellipses deviated significantly (by10 degrees, on average) from what would beexpected (perpendicular to the Galactic plane) ifthe electron density irregularities responsiblefor the scattering were to be “stretched” due to

the magnetic field strictly aligned parallel to theGalactic plane. This indicates additionalsignificant scatter-broadening contribution frommuch differently aligned density anisotropy,most likely associated with the North PolarSpur. Since the data on Zeeman pairs has alsorevealed (for the first time) signatures ofdifferential scattering for the two circularpolarisations, it was assessed, throughsimulations of diffractive effects, how Faraday-rotation-induced modification of phase screenscan indeed lead to different scatter broadenedimages in the two polarisations, when viewed at10 or so milliarc-second resolution. Thesesimulations support data revealing significantdifferential scattering on these angularresolutions. Through the various aspects seenfrom the W49N OH masers, the attractive, butyet unexplored, potential of the high-resolutionmaser observations for probing the interveningmagneto-ionic medium has become evident.This work was in collaboration with WM Goss ofNRAO (New Mexico, USA) and Jose E. Mendoza-

O n g o i n gR e s e a r c h

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Torres of the Instituto Nacional de Astrofisica,Optica y Electronica (Mexico).

In collaboration with C Vinutha and YogeshMaan, analysis of pulsar observations, madeusing the GBT-RRI multi-band receiver in 2009,was continued to obtain dedispersed pulsesequences at a range of frequencies between110 and 1,400 MHz, starting from many tens ofterra-byte size data that were recorded as rawvoltage time sequences. The data on the pulsarunder study showed the expected periodicdrifting sub-pulse modulation, and cartographictransform is applied to the data from a set ofbands to obtain respective slices of theemission cone, providing a tomography view.The fine details in this andother pulsars are beingstudied.

The calibrator scans in dualpolarisation showed linearvariation of the beam-widthwith wavelength, as wouldbe desired, indicating thequasi-Gaussian illuminationof the GBT dish byDeshpande to be similaracross frequency and E & Hplanes. The measuredbeam-widths imply edgetaper in the range of -17 to-20 dB, or about 75%aperture efficiency.However, the performanceabove 1 GHz (in two MBRbands) is poor, affectedprimarily by (a) anyimbalance in phasing of thetwo arms of the feed and (b) the large gainslope across the wide band, combined withrelatively higher spectral density of noiseintroduced by a fibre link.

A successful attempt was made to analyseabout 6,000 single pulses of PSR B1133+16using the 100-m Effelsberg radio telescope. Thepulse-to-pulse intensity modulations were

examined using longitude- and harmonic-resolved fluctuation spectral analysis of thehigh time resolution (60 microsecond) data, anda low-frequency feature associated withamplitude modulation was detected in thefluctuation spectrum. This feature is interpretedas corresponding to the circulation time (about30 times the spin period) of the underlyingsubbeam carousel. Despite the erratic nature ofthis pulsar, periodic pseudo-nulls were clearlyevident, with period exactly matching with thatreported at a much lower radio frequency. Thisperiod would indeed be the actual carouselcirculation time in the pulsar, particularly duringorderly circulation. This analysis was done in

association with SnehaHonnappa, WLewandowski, J Kijak, J Giland O Maron of the KeplerInstitute of Astronomy(Poland) and A Jessner ofthe Max-Planck-Institut fürRadioastronomie(Germany).

Deshpande worked onpending GMRT(re)observations of theVela pulsar wind nebulamade in 2011 and dataanalysis is in progress incollaboration with RichardDodson and Maria Rioja ofICRAR (Perth, Australia)and Wasim Raja and DaveMcConnell of ATNF(Australia). To complementthis observation, full-

Stokes imaging of the radio nebula using ATCAat C and X bands, in pulsar-binning mode wasproposed and accepted.

In X-ray astronomy, Charge Coupled Devices(CCDs) are used for both imaging anastronomical source as well as to measure theenergy spectrum of the source. These work onthe simple assumption that the X-ray photon

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flux reaching the CCD is very low so that nosingle pixel receives more than one X-rayphoton during one interval of CCD read-out. Thisimplicitly implies that all the charge detectedabove the threshold in any one CCD pixel isproportional to the energy of the incoming X-rayphoton. But for bright sources like the X-raybinaries, this assumption might not always holdtrue, in which case the observed energyspectrum is artificially hardened leading towrong modelling of intrinsic source spectrum.Motivated by this problem, Deshpande andHarsha Raichur analysed the situation of suchpile-up due to finite spatio-temporal resolutionin a general setting of mutually uncorrelatedevents that follow Poisson statistics, and havederived an elegant method for pile-upcorrection. This method is expected to find awide application.

Bipolar molecular outflows have been observedand studied extensively in the past, but somerecent observations of periodic variations inmaser intensity pose new challenges. Evenquasi-periodic maser flares have been observedand reported in the literature. Motivated by this,situations in binary systems were studied withspecific attention to the two observed features:the bipolar flows and the variabilities in themaser intensity. The evolution of sphericallysymmetric wind from one of the bodies in thebinary system, in the plane of the binary wasstudied. The approach included an analyticalstudy of rotating flows with numericalcomputation of streamlines of fluid particlesusing PLUTO code. It was found that theanisotropies seen in the rotating frame have thedesired character of bipolar flows and alsoappeared to be periodic (with binary-period) toan inertial observer for relevant sight-lines.Further, the potential maser spots in the sky-plane did not move and the minima in intensityvariation cycle repeated at regular intervals ofthe orbital period. These characteristics arenaturally produced in Deshpande’s modelwherein the variabilities observed in the maser

intensity were due to the density modulationresulting from the flow in the binary as seenfrom the simulations. This study was done incollaboration with Nishant Singh.

A recent numerical simulation, by Kumar andKumar, of the classical Langevin dynamics of acharged particle moving on a sphere placed in auniform static magnetic field had given a non-zero orbital diamagnetic moment in the long-time limit, i.e., in the steady state. Thisnumerical result appeared as a surprise in viewof the well-known Bohr-van Leeuwen theoremon the absence of classical orbital(dia)magnetism in thermal equilibrium. It has,however, been questioned inasmuch as theFokker-Planck (F-P) equation, associated withthe Langevin equation, was pointed out to besatisfied exactly and uniquely in the steadystate by the normally expected canonicalprobability distribution (i.e., the Maxwellianvelocity distribution) that does not involve theapplied magnetic field, and, therefore, giveszero magnetic moment. To investigate thisfurther, the simulation was repeated forprogressively smaller values of the chosenelementary time-step approaching zero, atwhich the magnetic moment was indeed foundto extrapolate to zero. This not only resolves thestated disagreement, but also suggests aninteresting possibility for realising a finitesteady-state orbital magnetic moment in certainclassical systems driven by stochastic-dissipative processes which are non-Markovianand do not obey the fluctuation-dissipationrelation, instead lead to a steady state.Deshpande worked in collaboration with NKumar of RRI and K Vijay Kumar of YaleUniversity (USA).

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Biman B NathBiman B NathBiman B NathBiman B NathBiman B Nath’s professional research interestsinclude interaction of diffuse gas with galaxies,galactic outflows, cosmic rays and intraclustermedium.

In his prior research, Nath has shown theimportance of radiation pressure in drivinggalactic scale outflows, in addition to thestandard scenario of driving the wind bythermal pressure. However, there does not existany comparison in the literature between theroles of these two processes vis-à-vis the data.Nath, along with PhD student Mahavir Sharma,studied the relative roles of ram and radiationpressure in light of the available data, andfound that radiation pressure becomesimportant for larger galaxies (of over 10^12solar mass) with star formation rate in excess of100 solar mass per year.

In collaboration with T Ensslin, C Pfrommer, MUhlig and V Springel of MPA Garching, Nath andSharma studied the effect of streaming cosmicrays on galactic winds. Cosmic rays exertpressure on the ambient gas and this processcan contribute to driving galactic scale winds.Nath and team studied these effects with anovel numerical implementation of cosmic rayphysics in a SPH simulation as well as withanalytical calculation. The results showed thatcosmic rays can drive powerful and sustainedwinds in low-mass galaxies (less than 10^11solar mass).

He also worked on the development of a 2-Dhydro-simulation code so as to study purelyradiation pressure driven winds from rotatingdisc galaxies. The simulation, developed by IChattopadhyay of ARIES, Sharma and Nath,showed for the first time the rotating structureof the wind gas as observed in some galaxiesand also confirmed their previous theoreticalresults. It was found that the resulting wind hasa conical structure and consists mostly of lowangular momentum gas lifted from the centralregion of the galactic disc.

Nath, in collaboration with S Majumdar andChaudhuri of TIFR, analysed data from 30nearby galaxy clusters (REXCESS sample) tostudy the profile of enhanced entropy and tocompare the observations with their previousyear’s analytical results. Their results showedthat the profile of energy deposition in terms ofgas mass is remarkably similar in all clustersand are peaked in the central regions. They alsofound that the total energy deposited isproportional to the cluster mass, as predicted afew years ago from work done here in thecontext of AGN feedback in clusters byRoychowdhury et al. Nath formulated theprocedure for extracting energy deposition fromthe observed cluster data.

A recent study has put forward a new spectrumfor the low energy protons in our galaxy, inferredfrom the observed gamma ray emission fromnearby molecular clouds. This spectrum showsa break at a few GeV. Nath and N Gupta fromRRI and P Biermann from MPIfR interpreted thisbreak as arising from a spectrum with singlepower law in momentum, as expected fromshock acceleration theory. They also showedthat this spectrum was consistent with otherindependent measures, for example, ionisationrate and spallation in our galaxy.

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In addition to his research, Nath was alsoinvited by RAA to work on a joint review paperwith Y Shchekinov on the topic of dust in theintergalactic and intracluster medium. Inaddition to summarising the currentobservational and theoretical understanding ofthe subject, they also provided many newestimates of different processes of depositionand survival of dust grains in the IGM.

BiswBiswBiswBiswBiswajit Pajit Pajit Pajit Pajit Paulaulaulaulaul’s research interests span X-raybinaries, transients, X-ray instrumentation anddata analysis. During the year, Paul’s workincluded developmental work for an X-raypolarimeter and ASTROSAT as well asinvestigation into the various aspects ofcompact X-ray sources.

Paul and his colleagues are working on an X-raypolarimeter for a future small astronomysatellite mission. X-ray polarisationmeasurement is a yet unexplored area and hasstrong potential for understanding severalimportant high energy astrophysics problems.During the year gone by, the followingdevelopmental work was carried out in thisfield. Contributors to the work included PVRishin, MR Golapakrishna, R Duraichelvan, CMAteequlla and many members of RAL and MES.

Fabrication of an engineering model ofthe X-ray polarimeter

Fabrication of two detector units, of whichassembly and preliminary tests on onehas been completed

Further modifications on the design of theevent processing electronics and detailedtests; similar developments happened onthe common electronics unit

Complete design and some preliminarydevelopment work on the housekeepingelectronics of the X-ray polarimeter

In collaboration with two teams at ISAC,Bangalore, and SAC, Ahmedabad, Paul workedon the development of the ASTROSAT-LAXPC

data reduction software. He also carried outextensive analysis of the LAXPC timing data,results from which have necessitated hardwarecorrections on the processing electronics.

He also worked on pulse phase resolvedspectroscopy in accretion powered pulsars;study of cyclotron line resonance features inaccreting pulsars; and optical reprocessing ofthermonuclear bursts in low mass X-raybinaries, among others.

In collaboration with Chandreyee Maitra of RRIand Sachindra Naik of PRL, Ahmedabad, Paulcarried out a timing and broad-band pulse-phase-resolved spectral analysis of a transientBe X-ray binary pulsar (1A 1118-61) observedduring its outburst in January 2009 usingSuzaku observations. The Suzaku observationswere made twice, once at the peak of theoutburst, and the other during its decliningphase. Pulse profiles from both observationsexhibit strong energy dependence with severalpeaks at low energies and a single peak above10 keV. A weak, narrow peak is detected at themain dip of the pulse profiles from bothobservations in the energy bands below 3 keV,indicating the presence of a phase-dependentsoft excess in the source continuum. The broad-band energy spectrum of the pulsar could befitted well with a partial covering cut-off power-law model and a narrow iron fluorescence line.They also detected a broad cyclotron feature ataround 50 keV from both observations, afeature common for accretion-powered pulsarswith high magnetic field strength. The pulse-phase-resolved spectral analysis showed anincrease in the absorption column density ofthe partial covering component, as well asvariation in the covering fraction at the dips ofthe pulse profiles, which naturally explainsenergy dependence of the same. The cyclotronline parameters also show significant variationwith pulse phase with an approximately 10 keVvariation in the cyclotron line energy and avariation in depth by a factor of 3. This can beexplained either as the effect of different

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viewing angles of the dipole field at differentpulse phases, or due to a more complexunderlying magnetic field geometry.

Along with Maitra, Paul carried out a detailedpulse phase resolved spectral analysis of thepersistent high mass X-ray binary pulsar Vela X-1 observed with Suzaku during June 2008. Thepulse profiles exhibited both intensity andenergy dependence with multiple peaks at lowenergies and double peaks at higher energies.The source shows some spectral evolution overthe duration of the observation and care hasbeen taken to average over data with minimumspectral variabilityfor the analysis.They modelled thecontinuum with aphenomenologicalpartial coveringhigh energy cut-offmodel and a morephysical partialcovering thermalcomptonisationmodel (CompTT)excluding the timeranges havingvariable hardnessratio and intensitydependence. Forboth the models,they detected acyclotron resonantscattering feature(CRSF) and itsharmonic at ~25 keV and ~50 keV. Both theCRSF fundamental and harmonics parametersare strongly variable over the pulse phase, withthe ratio of the two line energies deviating fromthe classical value of 2. The continuumparameters also showed significant variationover the pulse phase and gave some idea aboutthe changing physical conditions seen with thechanging viewing angle at different pulsephases and obscuration by the accretion streamat some pulse phases.

Paul made the discovery of a large number ofoptical bursts in the Low Mass X-ray Binary(LMXB) EXO 0748-676 simultaneous with thethermonuclear X-ray bursts. The X-ray and theoptical bursts were detected in a longobservation of this source with the XMM-Newton observatory. This has increased thenumber of thermonuclear X-ray bursts in theLMXBs with simultaneous optical detection byseveral factors. The optical bursts are found tohave a linear rise followed by a slow, somewhatexponential decay. Most of the optical burstshave longer rise and decay timescale comparedto the corresponding X-ray bursts. The X-ray and

optical excessphoton counts inthe bursts weredetermined thatallowed theresearchers to lookat the optical to X-ray burst fluenceratio for each burstand the ratio as afunction of the X-ray burst intensityand as a functionof the orbitalphase. The delaybetween the onsetof the X-ray burstsand the onset ofthe optical burstswere alsomeasured and

found to have an average value of 3.25seconds. No convincing evidence was found oforbital phase dependence of the followingparameters: X-ray to optical delay, rise time ofthe optical bursts, and optical to X-ray burstintensity ratio as would be expected if theoptical bursts were produced by reprocessingfrom the surface of the secondary star that isfacing the compact star. On the other hand, ifthe optical bursts are produced by reprocessingof the X-rays in the accretion disk, the onset of

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the bursts is not expected to have a sharp,linear shape as is observed in a few of thebursts in the LMXB. Simultaneous opticalobservations of the X-ray bursts in multiplewavelength bands will enable further detailedinvestigations of the reprocessing phenomena,including any non-linear effect of the X-rayirradiation. This study was done in collaborationwith M Archana and Lakshmi Saripalli of RRI.

Paul, along with Maitra (RRI) and Chetana Jainof Delhi University, reported the detection of aperiodic intensity modulation in the SupergiantFast X-ray Transient (SFXT) IGR J16207-5129 inthe long term 15-50 keV light curve obtainedwith the Swift Burst Alert Telescope (BAT)between MJD 53413 and 55888. Using theLomb-Scargle periodogram technique, a periodof 9.726 d was found. This can be the orbitalperiod of the X-ray binary. The light curve,folded with this period shows a complex shapewith a large modulation factor.

KS DwKS DwKS DwKS DwKS Dwarakarakarakarakarakanathanathanathanathanath’s research interests spanextragalactic astronomy, clusters of galaxies,halo and relic radio sources and the galaxy andinterstellar medium.

During the year gone by, Dwarakanath’s workincluded estimating HImass function at aredshift. To determine theevolution of the HIcontents of galaxies is avery important input intounderstanding the historyof gas content and starformation in the universe.While the study ofdamped Lyman-alphaclouds in absorption givesthe evolution of theaggregate HI content, thedetermination of HIcontent of a halo of agiven mass remains

elusive at high redshifts owing to the faintnessof individual halos in the emission line of HI 21cm-line. Recently, the first detection of HI at z1was reported based on cross-correlating thedensity field of optically-selected galaxies withknown red-shifts from the DEEP2 survey withthe redshifted HI emission by Chang et al. Theydetected the component of HI correlated withDEEP2 galaxies and established that most ofthe HI at z1 is associated with star-forminggalaxies observed by DEEP2. Detailedsimulation by Khandai et al reproduced theresults of Chang et al. These simulationssuggest that stacking of HI 21 cm-line emissionfrom galaxies of known redshifts can lead to adetailed reconstruction of the properties of HI inthese halos at z1. The DEEP2 redshift surveyhas made spectroscopic measurements of over25,000 objects in the redshift range 0.7 < z <1.5 in four fields. HI 21 cm-line observations oftwo of these DEEP2 fields were carried outusing the GMRT in the 610 Mhz band. Thisstudy was done in collaboration with Shiv Sethiand the data is now being analysed.

Dwarakanath, along with Chandreyee Senguptaand Tom Scott of Instituto de Astrofisica deAndaluca and DJ Saikia of NCRA, studied thespectacular displacement of HI during tidalinteraction in the interacting galaxy pair Arp 181

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(NGC3212 and NGC3215). They found thataround 90% of the detected HI displaced wellbeyond the optical disks of the pair with thehighest density HI located 70 kpc west of thepair. An HI bridge extending between the opticalpair and the bulk of the HI, together with theirHI deficiencies provide strong evidence that theinteraction between the pair has removed mostof their HI to its current projected position. TheHI distribution to the west of the pair has twoapproximately equal intensity peaks. The HIintensity peak farthest to the west coincideswith a small spiral companion that showsenhanced midinfrared (Spitzer), UV (GALEX) andH emission indicating intense star formingactivity. The HI intensity maximum closer to theArp 181 pair coincides with a diffuse opticalcloud detected in UV (GALEX) at the end of thestellar and HI tidal tails originating at NGC3212and, previously proposed to be a tidal dwarfgalaxy in formation. Future sensitive HI surveysby telescopes such as the Australian SquareKilometre Array Pathfinder (ASKAP) and theSquare Kilometre Array Interferometer shouldprove to be very powerful tools for identifyingtidal dwarfs at moderate and large redshifts toexplore in detail the evolution of galaxies in theuniverse.

Lakshmi SaripalliLakshmi SaripalliLakshmi SaripalliLakshmi SaripalliLakshmi Saripalli’s areas of research interestspan radio galaxies, including X-shaped radiogalaxies, host galaxy characteristics,intergalactic medium, environments of radiogalaxies, life-cycles of radio galaxies and radiogalaxy types.

During the year gone by, her main piece ofresearch related to radio galaxy lifecycles. In asurvey that imaged radio galaxies to very lowsurface brightness levels, she and hercollaborators discovered several candidate (20-30%) second-epoch radio galaxies. This,combined with the lack of a significant numberof fossil radio galaxies, suggested that radiogalaxies generally undergo several bursts ofactivity in their lifetime.

Based on the Australia Telescope LowBrightness Survey (ATLBS), Saripalli and hercollaborators presented a sample of extendedradio sources and derived morphologicalproperties of faint radio sources. One hundredand nineteen radio galaxies form the ATLBSExtended Source Sample (ATLBS-ESS),consisting of all sources exceeding 30'’ inextent and integrated flux densities exceeding 1mJy. Structural details, information on galaxyidentifications and source classifications werealso given by the team. The ATLBS-ESS, unlikesamples with higher flux-density limits, hasalmost equal fractions of FR-I and FR-II radiogalaxies, with a large fraction of the FR-Ipopulation exhibiting 3C31-type structures.Significant asymmetry in lobe extents appearsto be a common occurrence in the ATLBS-ESSFR-I sources compared with FR-II sources. Theresearch also included a presented sample of22 FR-Is at z > 0.5 with good structuralinformation. The detection of several giant radiosources, with size exceeding 0.7 Mpc, at z > 1,suggests that giant radio sources are not lesscommon at high redshifts. There was, inaddition, a sample of 28 restarted radio

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galaxies. The relative abundance of dying andrestarting sources is indicative of a modelwhere radio sources undergo episodic activity inwhich an active phase is followed by a briefdying phase that terminates with restarting ofthe central activity; in any massive elliptical, afew such activity cycles wherein adjacent eventsblend may constitute the lifetime of a radiosource and such bursts of blended activitycycles may be repeated over the age of thehost. The ATLBS-ESS includes a 2 Mpc giantradio galaxy with the lowest surface brightnesslobes known to date. This work was carried outin collaboration with R Subrahmanyan, KThorat, RD Ekers, RW Hunstead, HM Johnstonand EM Sadler.

Other research by Saripalli during the yearincluded high resolution imaging of the ATLBSregions, specifically, the radio source counts.The ATLBS regions were mosaic imaged at aradio frequency of 1.4 GHz with 6 arcsecangular resolution and 72 microJy/beam rmsnoise. The images cover 8.42 square degreessky area and have no artefacts or imagingerrors above the image thermal noise and,therefore, form a resource for attemptingautomated source identification andclassification algorithms. Multi-resolution radioand optical r-band images were used torecognise multi-component sources andprepare a source list. Radio source counts inthe flux density range 0.4-8.7 mJy wereestimated, with corrections applied for noisebias, effective area correction and resolutionbias. The resolution bias was mitigated to agreat extent by using low resolution radioimages, while effects of source confusion wereremoved by using high resolution images foridentifying blended sources. The ATLBS countsare systematically lower than previousestimates. The work underscores theimportance of using source lists –as opposed tocomponent lists – and correcting for the noisebias in order to precisely estimate counts closeto the image noise and determine the upturn at

sub-mJy flux density. This study was carried outalong with Thorat, Subrahmanyan, and Ekers.

N UdaN UdaN UdaN UdaN Udayyyyya Shanka Shanka Shanka Shanka Shankararararar’s areas of research interestinclude sky surveys, detection of epoch ofreionisation (EoR), an array for the detection ofepoch of recombination, and instrumentationand signal processing for radio astronomy.

Murchison Widefield Array (MWA) is a lowfrequency demonstrator operating in thefrequency range 80 MHz to 300 MHz. One ofthe main science goals of this array is to detectsignals from the EoR. Udaya Shankar, incollaboration with Harish Vedantham,Nithyanandan Thaygarajan and RaviSubrahmanyan, is investigating imaging modesand strategy for MWA to detect EoR. As a firststep, appreciating that limiting thecontamination from galactic and extragalacticforegrounds is critical to the success of MWA,the frequency structure of the 3D point spreadfunction (PSF) of MWA was studied. The 3D PSFhas the peculiar property that structures in thetwo angular dimensions get coupled tofrequency axis, which maps the Line of Sight(LOS) distance. In view of this, it is importantthat the PSF has acceptable frequency structureso that the residual foreground does notconfuse the EoR signature. In this work, a singleframework was used to understand the 3D PSFand foreground contamination. A formalism wasdeveloped to estimate the foregroundcontamination along frequency, or equivalentlyLOS dimension, and establish a relationshipbetween foreground contamination in the imageplane and visibility weights on the Fourierplane. Two dominant sources of LOS foregroundcontamination were identified – “PSFcontamination” and “gridding contamination”. Itwas showed that PSF contamination is localisedin LOS wavenumber space, beyond which therepotentially exists an “EoR window” withnegligible foreground contamination whereefforts will be focused to detect EoR. PSFcontamination in this window may be

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substantially reduced by judicious choice of afrequency window function. Gridding andimaging algorithms create additional griddingcontamination and Udayashankar and hiscollaborators proposed a new imaging algorithmusing the Chirp Z Transform that significantlyreduced this contamination. They alsodemonstrated the analytical relationships andthe merit of the new imaging algorithm for thecase of imaging with MWA. They have also beenworking on extending their framework onminimisation of foreground contamination inthe EoR window to obtain detailed statisticalestimates of two-dimensional distribution in k -space of three sources of uncertainty: classicalsource confusion, sidelobe confusion andthermal noise. They used the 128T arrayconfiguration proposed for the MWA in theirsimulations.

As a part of the RRI Aperture Array (AA) project,design and development of a high-speed ADC-FPGA unit was taken up so as to digitise fouranalogue bands of ~1GHz bandwidth each. Thedesign is based on two quad 10 bit ADCs and asingle Virtex-6 FPGA. An FPGA is required tograb the digitised data from the quad ADCs,channelise them into narrow sub-bands, andthen implement digital beam forming. UdayaShankar participated in discussions related tothe architecture of the board, carrying outinterferencemonitoring onsite to designthe analoguefront-end withsufficientheadroom forinterferingsignals andgeneration oftest vectors fortestingevaluationboards.

Udaya Shankar was involved with an all skysurvey at 150 MHz using the Mauritius RadioTelescope (MRT) along with Soobash Daiboo,Ramya Babu and Arvind Nayak. About asteradian of the sky (declination range -70° <Dec <-10°; sidereal hour range 00hr to 06hr)imaged during the previous year was analysedin detail. 3,837 sources in these images weredetected, of which 1,500 had matchingMolonglo Reference Catalogue of Radio Sources(MRC) sources. By carrying out a statisticalanalysis of positional errors and flux densitiesof sources common to MRC and MRT,corrections for positional errors were made inthe images and the flux density scale wasrevised. This showed the median spectral indexof sources between 150 and 408 MHz to be0.87, along expected lines. From the catalogue,a list of sources with steep spectral indices (< -1.3) was made for further studies.

The MRT has a very good UV coverage withbaselines going down to 2m both along EW andS directions. With this, they were able to detectall the 71 SUMSS extended sources listed in theJones & McAdam paper as well as 16 extendedsources not previously listed. The data analysisfor the RA range 7-18hr met with certaindifficulties and imaging of this range has beensuspended.

Precise measurements of the cosmic microwavebackground(CMB)anisotropies haveconstrained thebackgroundcosmology andinitial conditionsfor structureformation.However,understandingthe non-lineargrowth andastrophysicalevolution in the

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EoR has been difficult. Evidence to datesuggests a complex reionisation history. Directobservation of redshifted 21cm spin transitionof neutral hydrogen has been identified to be auseful method for detecting structures incosmological gas at high redshifts. Thistomography of redshifted 21cm line promises tobe a key probe of reionisation history. UdayaShankar and his collaborators are pursuing anexperiment to measure the 21cm global all skysignal with a single dipole antenna. As a firststep, they have taken up precisionmeasurements of the spectrum of the cosmicradio background. This requires frequencyindependent antennas of small electricaldimensions. They designed a wide-band fat-dipole antenna with a sinusoidal profile havinga frequency independent performance over theoctave band 87.5 to 175 MHz. The input returnloss exceeds 15 dB and the radiation powerpattern is frequency invariant and close tocosine square over the octave bandwidth. Thestructure has been optimised usingelectromagnetic modelling, and constructing aprototype has validated the design. This workwas done in collaboration with Raghunathan,Nipanjana Patra and Ravi Subrahmanyan.

In addition, as part of a flagship researchinitiative, Udaya Shankar has proposed an arrayto detect signals from the epoch ofcosmological recombination.

S SridharS SridharS SridharS SridharS Sridhar’s areas of current professionalresearch interests include dynamo action due toturbulence in shear flows,magnetohydrodynamic turbulence, stellardynamics in galactic nuclei, exoplanetarydynamics and states of light.

During the past year, Sridhar studied mean fielddynamo action in renovating flows with finiteand non-zero correlation time in the presence ofshear. Previous results obtained when shearwas absent are generalised to the case withshear. The question of whether the mean

magnetic field can grow in the presence ofshear and non-helical turbulence, as seen innumerical simulations, was examined. It wasshown, in a general manner that, if the motionsare strictly non-helical, then such mean fielddynamo action is not possible. This result is notlimited to low (fluid or magnetic) Reynoldsnumbers nor does it use any closureapproximation; it only assumes that the flowrenovates itself after each time interval.Specifying to a particular form of the renovatingflow with helicity, a standard dispersion relationof the dynamo in the small or large wavelengthwas observed. Thus, mean fields grow even inthe presence of rapidly growing fluctuations,surprisingly, in a manner predicted by thestandard quasilinear closure, even though sucha closure is not strictly justified. This work, donein collaboration with Sanved Kolekar andKandaswamy Subramanian of IUCAA, alsosuggested the possibility of obtaining meanfield dynamo growth in the presence of helicityfluctuations, although having a coherent helicitywill be more efficient.

Along with Jihad Touma of the AmericanUniversity of Beirut, Sridhar formulated thecollisionless Boltzmann equation for dense starclusters that lie within the radius of influence ofa massive black hole in galactic nuclei. Theapproach to these nearly Keplerian systemsfollows that of Sridhar & Touma. Delaunaycanonical variables were used to describestellar orbits and the fast Keplerian orbitalphases were averaged. The stellar distributionfunction (DF) evolves on the longer time-scaleof precessional motions, whose dynamics isgoverned by a Hamiltonian, given by the orbit-averaged self-gravitational potential of thecluster. Specialisation to razor-thin, planar discswas done and two counter-rotating (“±”)populations of stars were considered. Todescribe discs of small eccentricities, the ±Hamiltonian was expanded to fourth order inthe eccentricities, with coefficients that dependself-consistently on the ± DFs. The approximate

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± dynamical invariants were constructed andJeans’ theorem was used to construct time-dependent ± DFs, which are completelydescribed by their centroid coordinates andshape matrices. When the centroideccentricities are larger than the dispersion ineccentricities, the ± centroids obey a set of fourautonomous equations ordinary differentialequations. It was shown that these can be castas a two-degree-of-freedom Hamiltonian systemwhich is non-linear, yet integrable. The linearinstability of initially circular discs was studiedand a criterion for the counter-rotating instabilitywas derived. The rich non-linear dynamics ofcounter-rotating discs was then explored, withfocus on the variety of steadily precessingeccentric configurations that are allowed. Thestability and properties of these configurationsare studied as functions of parameters such asthe disc mass ratios and angular momentum.

Young stars in the galactic centre appear to beorganised in two counter-rotating systems

orbiting the centralblack hole. One ofthese is a stronglywarped disc,whereas the other isthicker and highlyinclined with respectto the former.Sridhar and TarunDeep Saini of IIScpresent a minimalmodel of thesegravitationallycoupled stellarsystems.

In collaboration withSaini and JAPstudent MamtaGulati, Sridharstudied the linearm=1 counter-rotating instability ina two-component,

nearly Keplerian disc. The goal was tounderstand these slow modes in discs orbitingmassive black holes in galactic nuclei. They areof interest not only because they are of largespatial scale – and can hence dominateobservations – but also because they can begrowing modes that are readily excited byaccretion events. Self-gravity being non-local,the eigen value problem results in a pair ofcoupled integral equations, which were derivedfor a two-component softened gravity disc. Thisintegral eigen value problem was solvednumerically for various values of mass fractionin the counter-rotating component. The eigenvalues are in general complex, being real only inthe absence of the counter-rotating component,or imaginary when both components haveidentical surface density profiles. The mainresults were as follows:

(i) The pattern speed appeared to be non-negative, with the growth (or damping)

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rate being larger for larger values of thepattern speed

(ii) For a given value of the pattern speed, thegrowth (or damping) rate increases as themass in the counter-rotating componentincreases

(iii) The number of nodes of the eigenfunctions decreases with increasingpattern speed and growth rate.Observations of lopsided brightnessdistributions would then be dominated bymodes with the least number of nodes,which also possess the largest patternspeeds and growth rates.

Again in collaboration with Touma, Sridhar alsoworked on developing a theory of resonantinteractions in multi-planetary systems in binarystellar systems. Of great interest are questionsconcerning the origins of the high eccentricitiesand inclinations inferred for the planetary orbits(from radial velocity and transit observations). Itwas estimated that, in at least three systems(upsilon-Andromedae, 55 Cancri and 777Gliese), there is a close commensurabilitybetween the binary mean motion and thesecular modes of oscillations of the planets.This resonant excitation of modes will befacilitated by capture into resonance during theplanetary migration phase. The status of thiswork is as follows:

The basic formalism was developedwhich involved setting up

– The Hamiltonian for the basicLaplace-Lagrange modes of a multi-planetary system

– The Hamiltonian for nonlinearinteractions between the LL modes(to fourth order in the eccentricities)

– The Hamiltonian for the binarydriving of the LL modes

A numerical code was written to solvethe Hamiltonian dynamics including

planetary migration (which is non-Hamiltonian)

Analytical methods were developed toanalyse the results (which show, ingeneral, chaotic motions)

The next steps will be to obtain results forspecific systems as well as to write a fullsimulation code without restriction to smalleccentricities or inclination.

Rajaram Nityananda of NCRA and Sridharsought to describe the four-dimensionalmanifold L which represents the “states oflight”. L is defined as the set of all planeelectromagnetic waves in vacuum, of unitintensity and frequency, propagating in alldirections and assuming any perfectly polarisedstate. For a given direction of propagation, theset of all polarisation states is the well-knownPoincare sphere. This needs to be generalisedto include all directions of propagation. Theyconstructed a geometric model in which L is theset of all elements, each of which is composedof three coplanar unit vectors. Work iscontinuing on this.

NaNaNaNaNayyyyyantara Guptaantara Guptaantara Guptaantara Guptaantara Gupta’s areas of professionalresearch interest include cosmic rays,neutrinos, gamma rays and gamma ray bursts.

Her work during the past year included thestudy of neutrinos from decaying muons, pions,neutrons and kaons in gamma ray bursts(GRBs). GRBs are the most luminous objects inthe universe, with the energy emitted by them ina few seconds being equal to the energyemitted by sun in its entire life time. It has longbeen speculated that these objects are also theacceleration sites of ultrahigh energy cosmicrays (UHECRs). As cosmic rays are deflected byinterstellar magnetic fields, it is difficult to tracetheir origin. However, the secondary neutralparticles (high energy photons, neutrinos)produced in the interactions of UHECRs withambient matter and radiations inside the

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astrophysical objects maintain theirdirectionality and can be used to probe theacceleration sites. In this context, Gupta andPhD student Reetanjali Moharana from IITBombay calculated the high energy neutrino fluxexpected on earth from GRBs including in detailthe different channels of neutrino andantineutrino production. In the internal shockmodel of gamma ray bursts, ultrahigh energymuons, pions, neutrons and kaons are likely tobe produced in the interactions of shockaccelerated relativistic protons with low energyphotons. These particles subsequently decay tohigh energy neutrinos/antineutrinos and othersecondaries. In the high internal magnetic fieldsof GRBs, the ultrahigh energy charged particles(µ+, π+, K+) lose energy significantly due tosynchrotron radiations before decaying intosecondary high energy neutrinos andantineutrinos. The relativistic neutrons decay tohigh energy antineutrinos, protons andelectrons.

Gupta and her colleague calculated the totalneutrino flux (neutrino and antineutrino)considering the decay channels of ultrahighenergy muons, pions, neutrons and kaons. Theyshowed that the total neutrino flux generated inneutron decay can be higher than that producedin µ+ and π+ decay. The charged kaons beingheavier than pions lose energy slowly and theirsecondary totalneutrino flux ismore than thatfrom muons andpions at very highenergy. Detailedcalculations onsecondary particleproduction havethe total neutrinofluxes and theirflavour ratiosexpected on earth.Depending on thevalues of the

parameters (luminosity, Lorentz factor,variability time, spectral indices and breakenergy in the photon spectrum) of a GRB, thecontributions to the total neutrino flux from thedecay of different particles (muon, pion,neutron and kaon) may vary and be reflected onthe neutrino flavour ratio.

Currently, IceCube and other large area neutrinotelescopes are trying to reach very highsensitivities in detecting astrophysicalneutrinos. IceCube has put limits on the flux ofGRB neutrinos. However, there are manyambiguities about their method of analysis. Thepossibility that GRBs could be sources ofUHECRs and neutrinos has not been ruled outso far.

Gupta also studied how high-energy gammarays originate from interactions of UHECRs inthe MilkyWay. Observational data fromextensive air shower experiments like Hires,AGASA, Yakutsk and Auger have been widelyused to understand the origin of UHECRs. Themaximum energy of cosmic rays from a cosmicaccelerator is determined by the size, magneticfield of the acceleration region, shock velocityand charge of the cosmic ray particle. Themaximum energy of the cosmic rays originatingfrom sources inside the Milky Way is not yetknown. Most of the cosmic ray sources in theMilky Way are located near its centre, and as a

result,galactocentricanisotropy isexpected in theUHECR spectrum.The observedUHECR spectrumdoes not showsuch anisotropyup to 1EeVenergy. Guptacalculated thePeV gamma raybackgroundproduced in the

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interactions of UHECR with the ambient matterand radiations during their propagation in theMilky Way. A large number of events for PeVgamma rays are expected in Km^2 areadetector in one year. If the primary UHECRs areproduced from galactic point sources thenthose point sources also emit PeV gamma rays.Gupta suggested that the detection ofgalactocentric PeV gamma rays in the futurewould be a signature of the presence of EeVcosmic accelerators in the Milky Way.

Other research by Gupta included spectrum andionisation rate of low energy galactic cosmicrays (GCRs), done in collaboration with Biman BNath and Peter L Biermann. The researchconsidered the rate of ionisation of diffuse andmolecular clouds in the interstellar medium byGCRs to constrain its low energy spectrum. Theyextrapolated the GCR spectrum obtained fromPAMELA at high energies and a recently derivedGCR proton flux from observations of gammarays from molecular clouds, and found that theobserved average galactic ionisation rate couldbe reconciled with this GCR spectrum if therewas a low energy cut-off for protons. They alsoidentified the flattening below a few GeV asbeing due to (a) a decrease of the diffusioncoefficient and dominance of convective loss atlow energy and (b) the expected break in energyspectrum for a constant spectral index inmomentum.

Research associate MaMaMaMaMayuriyuriyuriyuriyuri’s work involvedlooking into the power density spectra (PDS)and kHz Quasi Periodic Oscillations (KQPOs) ofsome low-mass X-ray binaries (LMXBs) indifferent broad band spectral states. This workwas done along with Biswajit Paul of RRI. Thechosen sources were those that commonlyshow KQPOs and whose long-term light curvesin the medium energy band (RXTE-ASM) andhard X-ray band (SWIFT-BAT) show significantspectral variations at large timescales. Mayuri isinvestigating the correlation between thepresence of KQPOs, their frequencies, rms,

quality factor, energy dependence of the QPOs,among others, with their broad band spectralbehaviour. Any dependence of the powerspectra on the broad band spectral state wouldgive important clues about the origin of thetemporal behaviour.

Mayuri identified sources by looking into thelong-term light curves in RXTE-ASM and SWIFT-BAT and extracted the power spectra of twosources. She also looked for all observationsthat have the required time resolution to beable to look for KQPOs as well as have theflexibility to extract power spectra over therequired energy band. As a result, powerspectra have been successfully extracted forabout 1,000 observations. Care was taken notto include data coming from the time intervalcontaining a type I burst, if present in the lightcurve. Further research is being done to look fora correlation between the existence of theKQPOs and their spectral state. The next stepfor this research would be to repeat thisinvestigation for other identified LMXBs and totry and explain the observed behaviour.

Photon arrival is widely accepted to be aPoisson random process. A Poisson process isdescribed as one having a constant probabilityof occurrence per unit time. An importantcharacteristic of a Poisson process is that it ismemory-less. In the context of photon arrival,the arrival of one photon is independent of thearrival of the previous or next photon. The Leahypower of a true Poisson process is 2. Dead timeof an instrument is the minimum amount oftime that must separate two events for them tobe distinguished and recorded. The dead timecan be contributed by multiple factors, such asthe response of the detector itself or theelectronics that follow the detector. In general,there are two broad classifications of dead time– paralysable and non-paralysable. Due to theeffects of the instrument dead time, thephotons detected no longer follow a trulyPoisson process and the power spectrumdeviates from the expected value of 2.

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For application to instrumentation onASTROSAT, Mayuri and Paul studied how thepresence of two paralysable dead timesaffected the power density spectrum. The twodead times were one for the detection of aphoton or a true signal, by the proportionalcounter, and the other for the detection of acharged particle and hence a false signal. Anunderstanding of the dead time effects wouldplay an important role in interpreting data fromthe instrument. They used random numbergenerators to simulate photon arrival as aPoisson process. Various random numbergenerators were investigated, which would givethe desired level of randomness. The test ofwhether the process is truly Poisson is that thepower spectrum of the resulting simulated lightcurve would have a value of 2, or very close to2, keeping in mind the limitations of thepseudo-random number generators. Furtherstudies will be to look at simulating the effectsof detector dead-times on the power densityspectrum.

Mayuri’s research for the year also includedsimulation and analysis software for the LargeArea X-ray Proportional Counter (LAXPC)instrument of ASTROSAT. Creating powerspectra from raw observation data is a timeconsuming process. It involves the additionalprocess of light curve extraction and writing thesame into the FITS format. On occasions, onlythe power spectra are of interest or only a quickview of them is needed before doing furtheranalysis. In such cases, it would be most usefulto speed up the process and obtain the powerspectra directly without having to redundantlyextract the light curve. Mayuri and Paul workedon a code to do just this. This code has beencurrently written for the GoodXenon mode ofRXTE-PCA (Proportional Counter Array) data andhas been tested successfully. The code can beadapted for ASTROSAT-LAXPC data when it isavailable.

Post doctoral fellow HarHarHarHarHarsha Raichursha Raichursha Raichursha Raichursha Raichur’s primaryresearch interests lie in the field of X-rayastronomy, particularly X-ray binaries.

During the past year, Raichur conductedresearch into the iron-line in X-ray binaries incollaboration with Gulab Dewangan of IUCAA,Pune. Broad, asymmetric, Fe K emission lineshave been observed in Active Galactic Nuclei(AGN) and Black Hole (BH) X-ray binaries usingobservations made by Chandra, XMM-Newton,etc. The observed emission lines are skewedand broad and hence believed to be originatingin the inner accretion disk. They have beenmodelled by incorporating Doppler andgravitational redshift effects, and hence areargued to enable one to constrain the inneraccretion disk radius and also the BH spin. Butconstraining model parameters of the Fe Kemission line in Neutron Star (NS) binaries isnot as straightforward. Firstly, the lines areweaker in comparison to the BH binaries andsecondly, characterising continuum spectrum ofNS binaries is difficult due to degeneratemodels. Suzaku NS binary observationsrevealed broad, asymmetric Fe K emissionlines. Even though the broadband coverage ofSuzaku observations mitigates the degeneracybetween different continuum models to someextent, the situation is not fully resolved due tothe complication by photon pile-up in the X-rayCCDs when observing bright sources. There isalso a lack of theoretical models for Fe Kemission lines in NS binaries. Raichur andDewangan are investigating Suzakuobservations of bright NS binaries that show theFe K emission line with the aim of doingdetailed spectral analysis of the data in light ofthe above stated complications.

Raichur studied the long-term spin periodevolution of Cen X-3. Cen X-3 is a persistenthigh mass X-ray binary that shows aperiodic X-ray ux variations at time scales larger than itsorbital period of 2.1 days. The binary-periodaveraged X-ray ux of Cen X-3 varies by a factorof more than 40. Long-term observations with

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Burst and Transient Source Experiment (BATSE)of the Compton Gamma-Ray Observatory(CGRO) found that Cen X-3 has alternate spin-up and spin-down intervals which last fromabout 10 to 100 days. However, detailed GINGAand RXTE observations revealed that there is nocorrelation between the observed X-ray ux andthe rate of spin-up/down of Cen X-3; hence itwas suggested that the observed X-ray Flux ofCen X-3 does not represent its mass accretionrate. But it is still not clear whether thevariations in the observed X-ray ux are only dueto obscuration of the central X-ray source by theaccretion disk or if at least a fraction of thesevariations are due to intrinsic change in the rateof mass accretion. Observed lightcurves fromthe Gamma-ray Burst Monitor (GBM) haveallowed the generation of X-ray pulse patternsat different observed X-ray ux and binary orbitalphase. These lightcurves also provide veryprecise measurements of the spin-up and spin-down rate of the pulsar. Raichur and MarkFinger of the National Space Science andTechnology Center (USA) are investigating ifthere are correlated variations in the pulsepattern with the orbital phase, X-ray ux andspin-up/down rate of the pulsar. For thesestudies, the observed pulse patterns areparameterised as Fourier series with 6harmonics, each with a different amplitude.Comparison of the amplitude of each harmonicwith the amplitude of the fundamentalharmonic for a series of pulse patterns showsthat most of the variation is in the fundamentaland the first harmonic. The two plan to studythis comparison with respect to the binaryorbital phase, the observed X-ray ux and therate of spin-up/down to understand the pulsaremission mechanism and the puzzle as to whyfor this particular X-ray Binary Pulsar theobserved X-ray ux does not correlate with therate of spin-up/down.

Mutually uncorrelated random events areroutinely monitored to estimate event spectra ofvarious natural phenomena. Suchmeasurements count the events occurring

within finite resolution of the detector used forthe observation. Within the resolution, howeverfinite, there is always a non-zero probability ofoccurrence of multiple events. Such multipleunresolved events are counted as one eventand the corresponding event strengths getadded up. This “pile-up” of events due to finiteresolution of the detector can result insignificant distortion of the intrinsic eventspectra. Raichur, in collaboration with AvinashDeshpande of RRI, suggested a solution tocorrect such observed piled-up spectrum suchthat the intrinsic spectrum is recovered. Themethod was successfully applied to piled-up X-ray photon energy spectra observed using X-rayCCD detectors used for imaging spectroscopy.

Post doctoral fellow HarHarHarHarHarshal Bhadkshal Bhadkshal Bhadkshal Bhadkshal Bhadkamkamkamkamkamkararararar’sresearch interests include the evolution of X-raybinaries, collective properties of X-ray binariesand binary star evolution.

During the year gone by, Bhadkamkar’s primaryengagement was the study of evolutionaryprocesses in HMXBs with a focus on tidalinteractions. Observations of a very high rate ofthe orbital period evolution call for a newexplanation of the evolutionary scenario. Thework involved modelling the tidal interactions inHMXBs and calculating the future evolutionaryscenario. Bhadkamkar, in collaboration withBiswajit Paul, explored if the renewedevolutionary scenario had any bearing on theformation rate of double neutron stars. He hasalso continued his work on the collectiveproperties of X-ray binaries, trying to model thebivariate PDF for HMXBs as a function ofluminosity and orbital period and also studyingthe Lx-SFR relation for HMXBs from theoreticalconsiderations. Another topic of interest forBhadkamkar was the modelling of stellarevolution using a recent public code MESA to beused for detailed modelling of the companion inX-ray binaries.

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Post doctoral Pancharatnam fellow ThThThThThyyyyyagarajanagarajanagarajanagarajanagarajanNithNithNithNithNithyyyyyanandananandananandananandananandan’s research interests coverobservational cosmology, extragalacticastronomy, dynamic radio sky and statisticalmethods and modelling in astronomy.

During the year gone by, his research includedestimation of foreground contamination in thedetection of signal from the Epoch ofReionisation (EoR) using the MurchisonWidefield Array (MWA) in collaboration with NUdaya Shankar and Ravi Subrahmanyan of RRI.The MWA is a next-generation radio instrumentcurrently under construction in WesternAustralia. It will consist of 2,048 dual-polarisation dipole antennas optimised for the80-300 MHz frequency range, arranged as 128“tiles”, each a 4×4 array of dipoles.

One of the three key projects related to theMWA is detection and characterisation ofredshifted 21cm neutral hydrogen signals fromthe EoR. Power spectrum measurements of theredshifted 21cm from EoR are difficult. The EoRsignal is extremely weak in comparison to theforeground emission of the galaxy andextragalactic sources and may requireconsiderable effort to distinguish theirsignatures from residual errors even aftercareful spectral modellingand subtraction of theseforegrounds. Previousresearch has shown thatthe inherent isotropy andsymmetry of the EoRsignal in frequency andspatial wavenumber (k)space make itdistinguishable fromsources of contaminationwhich lack such symmetry.An inherent mechanismfor foregroundcontamination via thefrequency dependentstructure (chromaticity) ofthe primary and

synthesised beams has also been developed,which becomes significant owing to therelatively large bandwidths associated with EoRobservations. A more recent study offers aframework to understand the localisation of thisforeground contamination from residuals inspatial scales in the line-of-sight direction. Italso shows that appropriate choices ofbandpass window functions and imagingalgorithms can significantly minimise levels ofsuch contamination in specific regions of k-space, termed as the “EoR window”.

Nithyanandan and his collaborators used thisone-dimensional framework to present detailedstatistical estimates of the distribution of threesources of uncertainty, namely, classical sourceconfusion, sidelobe confusion and thermalnoise, in two-dimensional k-space. The 128-tile(128T) array configuration proposed for theMWA has also been used in the estimates. Theycompared the relative magnitudes of thesedifferent sources of uncertainties and obtaineda more complete view of the estimates of theEoR power spectrum sensitivity characteristicsof the measuring instrument

The most important results of the nature ofcontamination are:

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The classical source confusion isrestricted to a narrow region in k-space

The sidelobe confusion is localised in awedge-like region in the 2D k-space

Thermal noise is distributed throughout k-space

The shape of the bandpass causes aspillover of the contamination into theEoR window

Choosing a Blackman-Nutall bandpasswindow significantly reduces the spilloverof the contamination in the EoR window

The different sources of contaminationhave been estimated for the snapshotmode of the MWA

Another area of study for Nithyanandan was thatof radio transients and variables, incollaboration with KS Dwarakanath and ShriKulkarni and his team from Caltech University(USA). This included follow-up studies with thePalomar Transient Factory (PTF) and GiantMeterwave Radio Telescope (GMRT).

The PTF is an experiment designed tosystematically explore the optical transient andvariable sky and fill the gaps in our present-dayknowledge of the optical transient phase space.There exist many types of either poorlyconstrained events (such as luminous rednovae, tidal disruption flares, etc.) or predictedbut not yet discovered phenomena (such asorphan afterglows of gamma-ray bursts). As inthe case of radio frequencies, dedicated wide-field instruments have the best prospect ofleading to significant progress.

While a number of surveys have attempted thischallenging task and provided importantcontributions to the understanding of time-domain science, they were designed tomaximise the discovery probability for selectedsource populations. Thus, large areas of thephase space remain poorly explored at best andare ripe for investigation with PTF. Thyagarajan’saim is to conduct follow-up studies of the radio

variables and transients related to his previouswork using the PTF, whose footprint largelyoverlaps with those of the SDSS and the FIRSTsurveys. He has proposed the use of the PTF toconduct follow-up studies on the 1,623 radiovariables and transients identified in the FIRSTsurvey. Around 55% of these sources have nooptical counterparts, including the SDSS. It isplanned to coadd the PTF pointings on thesesources with the goal of obtaining imagesdeeper than those of SDSS. If detected, this willhelp significantly in knowing more about thenature of the hosts of these objects. Sourcesthat SDSS has detected but been unable toclassify could be studied for their optical lightcurves from the PTF to arrive at their potentialclassification. Besides verifying the efficiency oftime-based classification schemes, assemblinga combination of radio and light curves fordetected and well-classified objects from SDSSusing PTF data is also planned.

Nithyanandan also conducted a follow-up studyof transients using GMRT. Based on light curvesthat satisfy either of the following criteria, 57transient-like candidates were identified:

1. the source is detected only in a singleepoch and the rest of the observationsresulted in non-detections, or,

2. the detection with the maximum fluxdensity is at least five times more thanthe observation with next highest fluxdensity irrespective of whether the latteris a detection or not, indicating a sharptransition in the light curve.

Even though the FIRST survey does not haveuniform coverage in time, it is a very sensitivesurvey over a large portion of the sky. Thus, it isexcellent at detecting variable and transient-likebehaviour in sources but poor at constrainingthe timescales and cadences of such behaviour.The chosen transients, which were well abovethe source detection threshold of the FIRSTsurvey, were to be followed up on in asystematic fashion specifically designed to

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study their behaviour with time. The flux densityinformation of these sources was used both asa function of the observation epoch as well asthe primary beam attenuation at the locationsin the fields they were observed, thereby, rulingout selecting spurious candidates owing tohighly attenuated primary beams and increaseduncertainties. The normalised flux densities ofneighbours as a function of the epoch ofobservations and primary beam attenuationwere well behaved, once again ruling out anysystematic problems such as with calibration orbad fields. The final list consisted of 20 of the57 sources.

The 610 MHz band of the GMRT yielding will beused to find a resolution that is close to theangular resolution of the FIRST survey. Inaddition, the simultaneous feed capability ofthe GMRT will be used to observe in the 233MHz band. This will allow the study of the

source’s chromatic behaviour in time (if any).The timescales of variability in these candidatesare expected to be between a few days andmonths. The galactic centre radio transientswere observed to have timescales of a fewmonths using the VLA and the GMRT at lowfrequencies. The target list consists of sourcesat high galactic latitudes, which are thus notexpected to be extragalactic. The proposedstudy aims to observe these candidates in twoepochs separated by three months. Deepenough sensitivity is essential to identify anyfaint and possibly extended structures in thehost galaxies, requiring two hours on eachsource at each epoch. This amounts to a total of80 hours of GMRT observing time, which hasbeen granted to Thyagarajan and hiscolleagues. One epoch of observations hasalready been completed and analysis of thedata is underway.

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LIGHTAND

MATTERPHYSICS

LIGHTAND

MATTERPHYSICS

41

The Light and Matter Physics (LAMP) group

comprises five motivated faculty members

and their students. The members of this

group are engaged in an area of light-matter

interaction that is a combination of Atomic,

Molecular and Optical (AMO) physics on one

hand, and intense laser field studies of

plasmas on the other. The group takes a

holistic scientific approach, where the fields

of theoretical, numerical and experimental

research complement one another.

O v e r v i e w

There are four labs that cater to the individualneeds of the LAMP members:

The Laser Cooling, Light Scattering Lab

The Ultrafast and Nonlinear Optics Lab

The Quantum Optics Lab

The Quantum Interactions (QUAINT) Lab

In addition, a lab for quantum information andcomputing (QUIC) has just been initiated.

The following pages summarise the major areasof research for the LAMP group. Each member’sindividual work during the last year is providedin the next section, giving the reader a moredetailed and technical description of theirrespective research activities.

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QUANTUM OPTICSQuantum optics is a field in physics that appliesquantum mechanics to study phenomenainvolving light and its interactions with matter.Since the first indication in 1899 that light maybe quantised, the field of quantum optics haswitnessed significant progress in ourunderstanding of light-matter interactions andmicroscopic systems. The major fields ofinterest in quantum optics include themanipulation of elemental particles like atoms,ions and molecules and the use of quantumoptics for quantum information. Fundamentalquestions regarding the nature of coherencetransfer between quantum light-matterinteractions are actively being pursued. Theexperiments include low-intensity probes foratoms that are prepared in a superpositionstate. Quantum Non-Demolition (QND)measurements of a quantum superpositionstate is also being actively explored bothexperimentally and theoretically.

LASER COOLING AND TRAPPINGLaser cooling and trapping is an area of physicsthat has largely expanded over the last decade.Presently, atoms can be cooled to extremely lowkinetic temperatures (as low as 1 microK) andtrapped for a time period of the order ofseconds. Such control over the motion of atomsallows researchers to probe their behaviourmore precisely than before. There are a numberof techniques to cool and trap atoms of alkalielements, with the most commonly used onebeing Doppler cooling. It involves three mutuallyperpendicular laser beams that intersect at thecentre of the chamber. A pair of magnetic coilsproduces a magnetic field that is zero at thecentre of the chamber, and increases radiallyoutward. Using appropriate wavelength andpolarisation of the laser beams, atoms can becooled by repeated absorption and emission oflight, and trapped by an inward force arising outof the combination of the polarised light beams

and the spatially varying magnetic field(Magneto Optical Trap or MOT).

At the laser cooling lab, electromagneticallyinduced transparency and related phenomenonwith cold atoms are studied. The nature anddepth of correlation of an atomic CPT statecreated during such interactions are the centraltheme of current research. Another area ofcurrent study is the nature of fluctuations in acollection of cold atoms.

ELECTROMAGNETICALLYINDUCED TRANSPARENCY (EIT)EIT is a quantum mechanical phenomenonwhere, under specific conditions, an absorptionline of a material can be cancelled changing itfrom opaque to transparent at that particularfrequency. To observe EIT, two highly coherentlasers are tuned to interact with three or morequantum states of the material. Considerableresearch activity has been devoted to this topicand RRI researchers are trying to build a strongfundamental understanding of thisphenomenon using both theoretical andexperimental methods.

QUANTUM WALK OF LIGHTA random walk is a mathematical description ofa trajectory where the successive steps arerandom. Classical random walks are used insearch algorithms when the searchedparameter space is random. They findapplication in the fields of computer science,physics, ecology, economics and psychology.Quantum walks are the equivalent of randomwalks in quantum computing and can form apart of a quantum algorithm. Members of thisdivision are now investigating the quantum walkof light in the frequency space.

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LIGHT PROPAGATION INRANDOM MEDIAMultiple scattering of light in random media,like fog, considerably reduces visibility. Thepropagation of light in random media is usuallydiffusive rather than ballistic. This leads to avariety of interesting phenomena like mirrorlesslasing, Levy statistics and weak and stronglocalisation, which have been subjects of theLAMP group’s recent studies. The work includesexperiments in colloidal suspensions ofdielectric or magnetic microspheres, both activeand passive. These are supported by Monte-Carlo simulations and theoretical analyses oflight propagation in such media. Theunderstanding of such phenomenon might opendoors for future novel optical devices.

NONLINEAR OPTICSThe nonlinear optical transmission of materialsystems finds applications in optical switches,saturable absorbers and optical limiters. Overthe years, RRI researchers have investigated thenonlinear optical properties of various types ofmaterials, with an emphasis on nanoparticlesand nanocomposites. These materials may besynthesised in the chemical room of the LAMPgroup. They are relatively new and showproperties that are quite different from theirbulk counterparts. Evolution of the nonlinearresponse in these media in the ultrashort(femtoseconds) timescales have beeninvestigated using ultrafast laser systems. Someof the interesting materials studied recentlywere ferrofluids and cobalt-in-carbonnanotubes. The experimental techniques usedare pulsed laser z-scan, degenerate four wavemixing (DFWM) and femtosecond pump-probespectroscopy. Experiments in white light z-scan,low-power z-scan and hyper-Rayleigh scatteringare underway.

LASER INDUCED PLASMASIt is possible to generate a plasma – the fourthstate of matter – in the lab using powerfulpulsed lasers. Such plasmas are nothing butshort-lived stars, and their study is aptly named“laboratory astrophysics”. The LAMPresearchers have studied the spectrum of laser-induced plasma emission from planar liquid jets(250 microns thickness) at atmosphericpressure. Presently they are generating ultrafastlaser plasmas from metal targets in vacuum.The emission spectrum is found to contain highenergy photons in the soft and hard X-rayregimes, as well as electrons and ions. Infuture, such table-top systems are expected toreplace larger particle accelerators in certainapplications including medical diagnosis.

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Andal NaraAndal NaraAndal NaraAndal NaraAndal Narayyyyyanananananananananan’s areas of currentprofessional research interests are quantumoptics and cold atoms. During the year,Narayanan’s research included microwave-optical non-linear coupling through CoherentPopulation Trapping (CPT) resonances. Anexperimental signature of transfer of coherencefrom the microwave frequency domain (around3 GHz) to the optical domain (around 1000TeraHertz) had been demonstrated during theprevious year (2010-2011). As a follow up ofthis work, the existing microwave cavity wasredesigned during 2011-12. This work wasdone in collaboration with Asha K and MeenaMS of RRI.

She also worked on a project, in collaborationwith Pantita P and Alex Lvovsky of the Universityof Calgary (Canada), that aimed to introduce anultra-narrow optical fibre (of diameter less thanthe wavelength of light used) into a Magneto-Optical (MOT) setup of ultra-cold atoms. Thestudy was done with a fibre pulling setup togenerate the thin optical fibre. The existing MOTsetup was interfaced with a high speed DACcard for this purpose. In addition, a new vacuummodule was set up with an octagonal chamber.An ultra-low pressures of 10^(-8) mbar wasachieved with a turbo pump after bakeout inthis setup.

O n g o i n gR e s e a r c h

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Hema RamachandranHema RamachandranHema RamachandranHema RamachandranHema Ramachandran’s areas of currentprofessional research interests cover quantumcomputing/quantum logic, light propagation inrandom media and novel optical applications ofnanomaterials.

During the year, Ramachandran pursued herwork in quantum logic on two fronts – usinglight and using atoms. Quantum logic withphotons and atoms requires the ability tomanipulate single atoms and to detect singlephotons. In addition, the protocol intended onbeing used requires the ability to control veryprecisely and rapidly the phase of light.Ramachandran’s efforts in the laboratory havebeen focused on achieving these capabilities. Inthis effort:

It was demonstrated that electronicallycontrollable precise phase shifts (as smallas 0.010) on timescales as short as~100ns may be imparted to light using theacousto-optic interaction. This hasprovided a new way of introducing phasenoise to light, and of controlling the extentof dephasing. This is of particularimportance in causing uniform spread of aquantum walker, desirable in a variety ofapplications like search algorithms, solarenergy harvesting, photosynthesis, andcommunications.This work was donein collaborationwith researchscholars NandanSatapathy andDeepak Pandeyand ProjectAssistant MSMeena.

With Pandey,Satapathy andSuryabrahmam,using appropriatelytailored radio-frequency input,Ramachandran

created light sources exhibiting differentphoton statistics. Further, the equivalenceof detection of statistics in classicalphotodetectors and single photondetectors was demonstrated.

She also worked on the building of acoincidence detector at the single photonlevel. This uses a pair of avalanchephotodiodes, the outputs of which are fedto an NI data-acquisition card. UsingLabVIEW, the system was programmed tocount coincidences in detection and savethem onto the computer for furtherprocessing if required. The system has atiming resolution of microsecond, limitedby the data-acquisition card and theWindows environment. This system hasbeen used to examine the second-ordercorrelation function of a laser source and apseudo-thermal source created usingacousto-optically imprinted random phasenoise. This was done along with Pandeyand Suryabrahmam.

The setup to trap a single atom is in the finalstages of completion. A few-atom MOT (100atoms) has been created and a dipole trap hasbeen superposed. A confocal imaging systemhas been built to observe the few atoms

46

collected in the dipole trap. The dipole trap nowneeds to be “tightened” to obtain single atom-trapping due to dipole-blockade. Ramachandranworked with Pandey and VSPs Soumya, Shahid,Mohammed Shafi and Akhil Raaj on thisproject.

The 3-D MOT for rubidium, which routinely trapsabout 109 atoms, has been functioning veryreliably and robustly. Absorption imaging of thecold atoms has been setup. From simple rate-dynamics analysis, a more efficient trappingunder certain detuning parameters of the laserbeam is expected. This is currently beingverified by experiments. This research was donein collaboration with Satapathy, Meena, projectassistant D Dhanalakshmi and visiting scientistVandna Gokhroo.

A recent theoretical work showed the existenceof a non-local geometric phase in the intensity-intensity correlations in a polarised Hanbury-Brown Twiss interferometer. This could beconsidered the classical analogue of the non-local, two-particle Aharonov-Bohm effect. Usingtheir technique of acousto-optic phase imprint,Ramachandran and her collaborators generatedpseudo-classical light and demonstrated thatthis non-local phase indeed exists, asevidenced by the modulation in the second-order cross-correlation and the absence of thismodulation in the self-correlation. Theexperiment was carried out with the help ofSatapathy and Pandey, while the theory wasworked out with J Samuel, Supurna Sinha andPoonam Mehta.

Ramachandran also studied light propagation inrandom media. The introduction of scatteringpolystyrene microspheres into a dye solution isknown to lead to enhancement of light emission(random lasing) due to the increased dwell timeof light within the medium caused by themultiple scattering. The introduction ofnanospheres is, however, not expected to leadto such an enhancement, because of the sub-wavelength size of the particle. Nevertheless,preliminary experiments done at RRI have

shown enhancement of light emission from adye solution upon the addition of magnetitenanospheres. This is believed to be due toDicke super-radiance and experiments arebeing conducted to verify this conjecture. Thisstudy was done in collaboration with visitingscientist Divya Sharma.

RRRRReji Philipeji Philipeji Philipeji Philipeji Philip’s research interests are in nonlinearoptical materials and laser induced plasmas.Nonlinear optical transmission findsapplications in optical switches, saturableabsorbers and optical limiters. Philip’s workincludes the investigation of the nature andultrafast temporal evolution of nonlinearity invarious materials, particularly nano-particlesand nano-composites. On the plasma front, hisresearch also covers ultrafast laser-inducedplasmas from liquid and solid targets keptunder high vacuum as well as ambientpressure. The plasma spectrum contains highenergy photons in the soft and hard X-rayregimes, as well as electrons and ions.

During the past year, he studied in detail theeffects of disorder on the nonlinear opticalproperties of CVD grown polycrystallinegraphene. Nanosecond Z-scan measurementsdone at two different wavelengths on single-layer, bi-layer and few-layer graphene filmsrevealed that the crystallite size significantlychanges the saturation intensity due to theinfluence of defect-induced states. He alsostudied the optical limiting properties of few-layer graphene (synthesised via reductionmethod), functionalised graphene, and metal-graphene composites. The strong nonlinearabsorption in graphene is attributed to the largenumber of structural defects on its surface. Itwas shown that the optical limiting performancein graphene can be improved through acidfunctionalisation and metal decoration, wheredefect-induced states and inter band transitionscontribute to the nonlinear absorption.

47

In another study, through a systematicmeasurement of nonlinear absorptioncoefficient in the nanosecond regime, Philipand his team confirmed the presence of mid-gap states which result in green luminescencein ZnO nanotetrapods. By annealing the samplein different atmospheres (O2, Ar and Zn), it was

found that the mid-gap state density is stronglyinfluenced by the Zn interstitials.

It is possible to generate radiation ranging fromTeraHertz frequencies (wavelength H” 10 µm) toγ-rays (wavelength << 0.1nm) from laser-produced plasmas. X-rays generated from laser-produced plasmas have been of interest owingto a variety of applications, including time-resolved X-ray diffraction, X-ray lithography andmicroscopy. Philip has been able to investigateplasma produced from pure targets such as Zn,Ni, C, Al and Cu, using high-energy laser pulsesof 7ns, 300ps and 100fs durations,respectively. In order to calculate the plasmaparameters, techniques employed includedlaser induced breakdown spectroscopy (LIBS),time-resolved spectroscopy and ICCD imaging.

LIBS is an atomic emission spectroscopytechnique which helps determine the elementalcomposition of the target under study. The goal

of the LIBS experiments was to generateplasma emission spectrum of pure elementalmetals and semiconductors under differentambient pressures. Plasma parameters such asplasma electron temperature and numberdensity are then calculated. The LIBS studieswere carried out in a pressure range of 760 Torr

to 10-6 Torr.

Time resolvedspectroscopicmeasurementsinvolve themonitoring of time-dependent evolutionof emission intensityof one or moreplasma spectrallines. Time resolvedstudies wereconducted in C, Zn,Ni and Cu targetsusing amonochromator-PMTcombination. ICCD(intensified charge

coupled device) imaging was used for takingphotographs of the plasma plume at differenttime delays and gate delays, to record theevolution of the plasma plume over its lifetime.

Sadiq RangwSadiq RangwSadiq RangwSadiq RangwSadiq Rangwalaalaalaalaala’s areas of current professionalinterest include ultra-cold molecules andquantum interactions. During the past year,Rangwala continued experimental work on theatom ion molecule, which is now producingresults.

An apparatus and technique whichsimultaneously traps ions and cold atoms withspatial overlap was designed, motivated by thestudy of ion-atom processes at temperaturesranging from hot to ultra-cold. This is a largelyunexplored domain of physics with cold trappedatoms, and the use of the set up for severalproblems in physics and chemistry were looked

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into. For this, Rangwala worked in collaborationwith K Ravi, Seunghyun Lee and Arijit Sharma ofRRI and G Werth of the Institut für Physik,Johannes Gutenberg-Universität Mainz(Germany).

A mixed system of cooled and trapped, ions andatoms paves the way for ion assisted coldchemistry and novel many-body studies. Due tothe different individual trapping mechanisms,trapped atoms are significantly colder thantrapped ions, therefore in the combined system,the strong binary ion-atom interaction results inheat flow from ions to atoms. Conversely,trapped ions can also get collisionally heated bythe cold atoms, making the resultingequilibrium between ions and atoms intriguing.The sympathetic and swap cooling of trappedions by cold atoms in a magneto-optically trappwas demonstrated experimentally by Rangwalaand his colleagues. Rubidium ions (Rb+) cool incontact with MOT Rb atoms, contrary to thegeneral expectation of ion heating for equal ionand atom masses. The cooling mechanism isexplained theoretically and substantiated withnumerical simulations. The resonant chargeexchange (RCx) collisions, which allows swapcooling of ions with atoms, wherein a single

glancing collision event brings a fast ion to rest,was studied.

The atom loss rate from an MOT due to ion atominteraction is characterised on the basis ofexperiments, where trapped ions and MOTatoms are spatially overlapped. Using a set ofrate equations, the dynamics of the MOT duringthe photo-ionisation of the 85Rb in the 5p3/2state to ionisation continuum was studied.Subsequently, the dynamics of a combined trapwere also studied. These experiments allow themeasurement of atom loss rate as a function ofintensity of the light source used for thephotoionisation.

Rangwala also studied the photo-association ofmolecules from cold atoms in the presence oftrapped ions. Cold molecules are created out ofcold atoms either by a photo-associativeprocess or by resonant free-bound scattering.The photo-associative path was explored, butwith a crucial difference. The association wasattempted in the presence of trapped ions. Thisis the first such experimental study anywhere inthe world. The experimental results showed asignificant decrease in the rate at whichmolecules are associated from the free atoms,over a limited but continuous range of

associationenergies. Twosignificantpossibilities thatcould yield suchsignatures are (1)the presence ofions inhibitsmolecular photo-association or (2)the ions opendissociationchannels, and thedissociatedmolecules arerecaptured in theMOT. Theoreticalanalysis and

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critical detailed analysis of the experimentaldata should allow the determination of thedominant pathway.

Rangwala’s research during the year includedthe study of atom-cavity interaction. The coldmolecules project mentioned above needsextremely low light level detection. The mostsensitive detection that is possible is resonantdetection via cavities. Before attempting coldmolecule detection, the technique for coldatoms must be proved. This involved anexperiment each with negative logic switchingand positive logic switching.

The transmission properties of a cavitycontaining atoms on resonance with laser lighton resonance with the cavity, and the atoms inthe cavity mode, was studied. Severalinteresting features in the laser atom-cavitysystem were explored. Most dramatically, thecavity mode can be completely switched OFFand ON by addressing the atoms in the cavitymode from the side. While the experiments areprocedurally quite similar, the theoreticaldescription is quite different and so are some ofthe effects observed.

A follow-up experiment for switching wasconstructed with potassium (K). The KD2spectrum is very different from the Rb D2spectrum and therefore significant differencesare expected in the switching behavioureffected by the K vapour. The experiment wasconstructed and the atom cavity properties forthis system were studied with great care.However no switching behaviour was observeddespite best efforts. One possibility is that the Kvapour pressure is too low for this experimentand this will be checked in the coming months.This is an interesting development and will beexplored in the future mainly by projectstudents.

An experiment for Molecule-Ion-Cavity-Atom(MICA) trap was tested and proven in the spanof this year. In this case, Rangwala and hiscollaborators developed the possibility of

trapping multiple species of atoms, ions andmolecules simultaneously, within a high finessecavity which is a trap for photons. All of thesetraps converge around a volume ofapproximately 107 cubic micro meters andallow for the interactions between theseparticles and fields to be probed at some of thecoldest temperatures possible. Notablesuccesses on this experiment during the yearinclude:

The creation of stable and controlled coldatoms in the cavity mode: This was by nomeans easy because the cooled atoms areexpected to couple light into the cavitymode, which would disrupt the lasercooling of the atoms. The extent of thedisruption in the cooling process is noteasily calculable and so it is best to do theexperiment. The creation of the MOT in thecavity mode was quite successful and oneimportant objective was realised.

Coupling of light from the cold atoms intothe cavity: The light coupled from theatoms into the cavity was very significantin intensity and was coupled into a varietyof modes. While this was expected, thedensity of modes populated was too largeto work productively with. Systematiccharacterisation of the experimentaloperating conditions allowed thesuppression of most of the unwantedmodes and focusing attention on a fewstable modes.

Weak and strong coupling of atoms to thecavity: When the cavity, which is an opticalresonator, is tuned so that it is resonantwith the atomic medium contained within,there are two broad ranges of operation,(1) the weak coupling regime and (2) thestrong coupling regime. This cavity hasbeen designed to be in the weak couplingregime for a single atom within the cavitymode. However, when the number ofatoms in the mode increases to about a

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1,000, the atom cavity system goes wellinto the strong coupling regime. This is amajor milestone for the experiment as itopens the window to cavity QED on theseexperiments, as well as allowingexperiments with small numbers ofphotons and atoms, where the systemproperties can be measured usingfrequency measurements instead ofintensity measurements. Extension of thisclass of measurement has never beendone for any molecular system anywhereand is now an important experimental goalfor the future.

Many experiments in the QuaInt lab concernparticles and transition from isolated particlesto cooperative behaviour and response. Theseare regimes where single particle physics, whichforms the basis of our overall understanding ofrelated physics, falls seriously short of providingadequate explanation for the experiments.

Thus, a parallel programme of simulation of theexperimental systems is conducted so that adetailed understanding of the physics emerges.During the past year, several numericalsimulations were implemented to enable abetter understanding of the physics problemsthrown up by the experiments.

The simulations include:

Molecular dynamics simulations whichevolve thousands of interacting ionssimultaneously in the ion trap: This allowsresearchers to follow the evolution of “n”interacting ions at a given temperaturewith time. It helps them relate to thesituation in the experiment at an ion level.

Multiple scattering of trapped ions withtrapped atoms: This allows the study ofthe evolution of “n” non-interacting ions,one at a time, within an atomic gas. Theion-atom scattering is calculated in detailand the evolution of the trapped ionwithin the atomic cloud and its change inenergy is tracked with time. The elastic

and the inelastic (charge exchange)channels are both calculated within thissimulation, which helps make connectionswith the experimental situation.

Atom light and atom cavity interactions: Anattempt was made to understand thedynamics of the state population in thepresence of the multiple light fields withvarious intensities and detuning. Thespecifics for these simulations areevolving to address the physics comingout of the MICA experiment.

Molecular potentials and moleculeformation simulation: This is a very criticalsimulation for future molecular formationexperiments. Here it is required todetermine the asymptotic molecularpotentials so that the atom-moleculetransition rates and populations can beaccurately determined. What makes thesesimulations exceedingly challenging isthat the potentials are required to veryhigh accuracy to help with the experimentinterpretation and to have the requiredpredictive value to plan new experiments.

Postdoctoral fellow T PriyT PriyT PriyT PriyT Priya Ra Ra Ra Ra Roseoseoseoseose’s researchinterests are ultrafast laser induced plasma inliquid droplets.

Laser produced plasmas are known to emitintense electromagnetic radiation. It is possibleto generate radiation from Tera Hertzfrequencies to gamma rays. Apart from thefundamental interest in diagnosing thedynamics of laser plasmas, X-rays generatedfrom laser-produced plasmas have been ofinterest owing to the variety of applications liketime-resolved X-ray diffraction, X-ray lithographyand microscopy. The advantage of using adroplet as the target is that it can act like a lensand focus the light incident on it. Thus theelectric field inside the droplet can act like alens and focus low-intensity light incident on thedroplet can far exceed the incident laser field.

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As an initial step, Rose set the experiment torun in atmospheric pressure. Micro droplets ofethanol were generated using a piezo-capillary.It was driven by applying a signal of amplitude5V with 1MHz. The laser used for producing theplasma is a Ti:sapphire chirped pulseamplification system at 800 nm. The laser isfocused to the droplets using a convex lens.Rose is currently working towards synchronisingthe laser pulses with the droplet jet. The plasmawill later be characterised by various techniqueslike spectral analysis, time-resolved studies, etc.

J Solomon IvJ Solomon IvJ Solomon IvJ Solomon IvJ Solomon Ivananananan’s area of current professionalresearch interest is the quantum informationtheory. During the year gone by, Ivan continuedhis research into unsolved problems such asthe entanglement of formation for two-modeGaussian states. He also spent substantial time

in attempting to understand the theory ofpositive maps. He has had frequent discussionswith Deepak Pandey, Nandan Sathpathy andButi Suryabrahmam of RRI with regard to theongoing experiment on tailoring a classicalresource. The attempt of the experiment is toconvert a coherent light source from a laser to alight source with a desired classical feature. Thesimplest example is the conversion of coherentlight to thermal light. Such a convertability canlead to various practical applications. Ivan’sassistance to the above mentioned threeexperimentalists has essentially been on thetheoretical side, especially on suggesting tothem a scheme which directly implements theSudarshan diagonal representation (at aclassical level) in achieving the desired end.Data acquisition is ongoing, with the acquireddata thus far being in line with the theory.

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SOFTCONDENSED

MATTER

SOFTCONDENSED

MATTER

53

The Soft Condensed Matter (SCM)

group concentrates its research

activities in the area of liquid crystal

synthesis, characterisation and other

analysis of their physical properties. The

group has also expanded its activities to

investigate other soft condensed matter

like polymers, colloids, amphiphilic

systems and nanocomposites.

O v e r v i e w

Theoretical and experimental research todayincludes the well-established area of liquidcrystal synthesis and characterisation as well aselectrochemistry and surface science, liquidcrystal displays, rheological studies of softcondensed matter and biophysics. The researchenvironment of the SCM group is highlyinteractive with constant knowledge sharingand exchange of ideas among chemists,electrochemists, condensed matter physicists,theoretical physicists and members withstatistical physics expertise.

The following pages summarise the major areasof research for the SCM group. Each member’sindividual work during the last year is providedin the next section, giving the reader moredetailed and technical description of theirrespective research activities.

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LIQUID CRYSTALSThe chemistry wing of the SCM group isinvolved in the synthesis and characterisation ofa number of molecules, including bent-coremesogens, discotic mesogens andnanocomposites. Over 700 bent-core mesogens– mesomorphic banana-shaped or bent-coremolecules – have been synthesised andcharacterised. In addition to many novelmesophases, these compounds showinteresting features such as spontaneouselectric polarisation and chiral structures madeup of achiral molecules. Several new liquidcrystalline phases and phase sequences havealso been achieved.

The lab has also designed, synthesised andcharacterised novel discotic liquid crystals thatexhibit remarkable electronic and optoelectronicproperties, including various monomeric,oligomeric, polymeric and ionic liquid crystallinematerials containing disc-like mesomorphicunits. The synthesis of liquid crystallinematerials using microwave heating has alsobeen carried out with a view to find quick andenvironment-friendly synthetic routes.

The incorporation of nanomaterials like gold-nanoparticles and carbon nanotubes in thesupramolecular order of liquid crystals is likelyto lead to novel materials for many applications.Such nanocomposites have been prepared andare being characterised.

The SCM group also studies phase transitions,the structure and physical properties ofthermotropic liquid crystals and their mixturesas well as various types of topological defectsand patterns in liquid crystals. Recent yearshave seen the discovery of several new liquidcrystalline phases, such as the undulating twistgrain boundary phase and the biaxial Smectic-Aphase. Another area of interest is instabilitiesand pattern formation in thermotropic liquidcrystals under shear flow and/or externalelectric fields. Surface-induced effects in liquidcrystals are also being explored.

Research is also being done to help reducepower dissipation and hardware complexity ofdrive electronics in passive matrix Liquid CrystalDisplays.

COLLOIDSInvestigations are being carried out into theageing dynamics of colloidal systems, such asaqueous suspensions of synthetic clay.Rheological techniques are used to study theeffects of strain history and sample age on theirrelaxation spectra. The results demonstrate thatstress relaxation measurements can beeffectively used to estimate the relaxation timesof these samples. Dynamic light scattering(DLS) and diffusing wave spectroscopy (DWS)experiments are also being set up to study thedynamics of these complex fluids.

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different sterol molecules is being studied usingX-ray diffraction and fluorescent microscopytechniques, with a view to understand theorganisation of these biologically importantmolecules in the membrane.

POLYMER PHYSICSInvestigations are being made into themorphologies of polyethylene single crystals.The crystallisation of high molecular weightpolyethylene from melt or solution leads to theformation of tent-like structures. The stability ofthese structures has been probed using a free-energy expression based on membraneelasticity. Tent-like structures have been foundto arise due to the tilt of the polymer chainswith respect to the layer normal.

BIOLOGICAL PHYSICSThe group’s study of cellular dynamics is drivenby the primary interest to understand forcegeneration, locomotion and transport processesin cells, including neurons. For this, they havedesigned novel experiments to performquantitative measurements on a variety ofsimplified cell systems. They are also designingexperiments to investigate stem celldifferentiation and patterning. This is aninterdisciplinary approach, which involves activecollaborations with biologists and theoreticalphysicists, at both local and international levels.

PHYSICAL CHEMISTRY OFSURFACESThe principal research subjects in this areainclude the study of supercapacitors as energystorage devices, the effect of applied magneticfield on electrodeposition, studies on molecularself-assembly of organic thiol molecules onnoble metal surfaces, and carbon nanotubes forelectron transfer studies as well as a chemicalsensor.

The SCM group has set up a Hele-Shaw cell tostudy the fingering instability at the quasi two-dimensional interface between an ageing claysuspension and a Newtonian fluid. The effectsof differences in the densities and viscosities ofthe two fluids on the fingering instabilities arebeing studied.

AMPHIPHILIC SYSTEMSRheology of micellar soft-solids: Pluronictriblock copolymers self-assemble to formmicelles in aqueous solutions as a result oftheir amphiphilic nature. The temperature-concentration phase diagram of this system,which exhibits the intriguing phenomenon ofinverse crystallisation, has been determinedfrom rheological data. These studies clearlydemonstrate the soft solid-like nature of thesematerials.

Magnetic suscesptibility studies: Studies of themagnetic susceptibility of micellar solutionsand lyotropic nematic liquid crystals provideinsights into the role of bound water andmolecular organisation in these systems.Similar studies on inverse micellar systems arecurrently underway.

Phase behaviour of ionic surfactants: Theinfluence of strongly bound counterions on thephase behaviour of ionic surfactants is beinginvestigated using X-ray diffraction andpolarising light microscopy. The aim of thesestudies is to look at novel surfactant aggregatemorphologies and novel phases induced bythese counterions.

Structure of DNA-surfactant complexes: Theinfluence of different types of counterions onthe structure of DNA-cationic surfactantcomplexes has been investigated using X-raydiffraction techniques. Novel structures ofthese complexes are found to occur in thepresence of strongly bound counterions.

Organisation of sterols in membranes: Thephase behaviour of lipid membranes containing

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O n g o i n gR e s e a r c h

Arun RArun RArun RArun RArun Roooooyyyyy’s current research interests includephase transitions and electro-optic properties ofliquid crystals, mean field phenomenologicalmodelling, and the physics of nano-materialsand nano-composites.

During the year gone by, Roy continued hisinvestigation from the previous year of thephase behaviour and the physical properties ofa new homologous series of compoundsconsisting of the hockey-stick shaped moleculesthat were synthesised in RRI’s chemistrylaboratory. This study was in collaboration withBK Sadashiva, R Pratibha, Meenal Gupta and SRadhika of RRI. Polarising optical microscopy(POM), differential scanning calorimetry (DSC),X-ray diffraction (XRD) and dielectric studieswere carried out to characterise the differentphases. The team reported experimentalevidences for two new fluid lamellar phasesexhibited by a homologous series of bent-corehockey-stick shaped molecules having triclinic

point symmetry of the layers. The packing ofthese bent-core hockey-stick shaped moleculesin the layers leads to an apolar intercalatedstrongly biaxial layer structure in these tiltedsmectic phases. These smectic phases are thelowest symmetry achiral liquid crystallinephases reported so far in the literature.

Along with the same team, Roy reported on thetwo types of vitrified states formed from thedark conglomerate (DC) liquid crystal phase bytwo members of a homologous series made ofbent-core molecules under different coolingprocedures. These states were characterisedusing POM, DSC, XRD, electro-optics, dielectricspectroscopy and atomic force microscopy. Theresults showed that though the vitrified stateformed on gradual cooling of the sample fromthe DC phase has some glassy feature, it isfragile and unstable against crystallisation overtime. On the other hand, direct quenching of theDC phase to room temperature results in

57

stronger glass formation. It was proposed thatthe vitrified state obtained on progressivecooling of the DC phase may have someanalogy to strain glass and that the DC phaseitself may be rather like unfrozen starin glass.

Another of Roy’s research themes for the yearwas the design and synthesis of six new seriesof anthraquinone-based monomers and dimersas well as studies on their structure, specificallythe property relationship with respect to theirliquid crystalline properties. This research wasin collaboration with Veena Prasad andstudents NG Nagaveni and K Gayathri of theCentre for Soft Matter Research, Bangalore. Thechemical structures of these newly synthesisedcompounds were characterised by IR, NMR andmass spectroscopy. The liquid crystallineproperties were investigated using POM, DSCand XRD studies. Most of the compoundssynthesised here were found to be liquidcrystalline. In many cases, the mesophasesstabilised up to room temperature. A variety ofmesophases was exhibited – colr, colh, DL andan unidentified mesophase, Roy and hiscollaborators attempted to propose a molecularmodel in the discotic lamellar phase of one ofthe dimer compounds based on the X-ray dataobtained.

Roy, with Prasad and Nagaveni, also designed,synthesised and reported mesomorphicproperties of six new homologous series of azo– substituted bent-core compounds. Theyinvestigated the effect of different types oflinkage groups and their direction of linking onthe mesomorphic properties. The study wasfocused on the photochromic bent-corematerials, and all the compounds synthesisedconsisted of an azo linkage in their moleculararchitecture, in addition to other linkage groups.The molecular structures of these newlysynthesised compounds were characterised byspectroscopic methods. The liquid crystallineproperties were studied using POM, DSC, XRDand electro-optical studies. Mesophasesobserved in these compounds were N, B1, B2,

SmA, SmAdPA. It was found that the type anddirection of linkage group do affect the thermalrange or sometimes even the nature of themesophases. Photo-induced effects on B2mesophase of some of the selected compoundswere also carried out.

D VijaD VijaD VijaD VijaD Vijayyyyyaraghaaraghaaraghaaraghaaraghavvvvvananananan’s areas of professionalresearch interests span nanoparticle-liquidcrystal composites, magnetic properties andphysical studies.

During the year, part of his research was basedon his interest in studying the massdiamagnetic susceptibility of micellar systems ingeneral and lyotropic liquid crystal systems inparticular to look for any structure-(magnetic)property correlations. He carried out magneticsusceptibility studies on a ternary lyotropicliquid crystal system [sodium decylsulfate(SdS)/decanol/water] for two different concentrationsof the constituents. This system exhibitednematic, isotropic and hexagonal phases onheating. The isotropic phase in this systemexhibited admixtured and pure phases.Correspondingly, findings included atemperature dependent susceptibility at lowtemperature and a temperature independentsusceptibility at high temperature isotropicphases. Diamagnetic anisotropies in thenematic phases of these samples werecalculated by extending the pure isotropicphase susceptibility in the nematic region. Forthe sample containing a high concentration ofsurfactant and low concentration of alcohol, thediamagnetic anisotropy value is small and foundto be temperature independent. In the case ofthe sample containing a low concentration ofsurfactant and high concentration of alcohol,the diamagnetic anisotropy is about six timeshigher and also temperature dependent. Thismarked difference in diamagnetic anisotropybetween the two samples is attributed to thedifference in shape of the micelles present inthese samples.

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Vijayaraghavan also carried out differentialscanning calorimetry (DSC), magneticsusceptibility and electrical conductivity studiesas a function of temperature on these ternarylyotropic liquid crystal systems. On heating, theDSC thermogram exhibited peakscorresponding to nematic and hexagonalphases. However, on cooling, the peaks wereabsent, indicating that the liquid crystallinephase is absent on cooling the system.Temperature dependent hysteresis was found inthe electrical conductivity and magneticsusceptibility studies as well. The hysteresis inthe diamagnetic susceptibility was attributed tothe difference in temperature dependence ofmicellar sizes on heating and cooling. Theinference from these studies is that changes inthe micellar sizes may lead to changes in theviscosity of these systems and leads to theobserved hysteresis in the electricalconductivity of the systems.

He also carried out mass diamagneticsusceptibility, ACand DC electricalconductivitystudies on twononionic micellarsystems namely,Triton X-100 (TX-100)/water andBrij-35/watersystems. It isknown that the TX-100/water systemexhibits hexagonal(H) and isotropicphases (I) for 40to 60 wt% of TX-100 in water. TheTX-100 systemalso exhibitscloudingbehaviour onheating resultingin a two-phase

region consisting of micellar rich and micellarpoor regions in water. Discontinuous changes atthe HI phase transition temperatures as well asat the cloud point temperatures in the TX-100system were found. Comparing the reportedtemperature dependence of the micellar sizesstudied through NMR with that of magneticsusceptibility, it was inferred that thediamagnetic susceptibility is directly related tothe sizes of the micelles. It was found that theelectrical conductivity follows Arrhenius relationand exhibits slope changes at the cloud pointtemperatures in the conductivity-temperatureplots. Vijayaraghavan calculated the activationenergies for conductivity in these systems andfound them to depend on the concentration ofthe surfactant. This led to the inference that theAC electrical conductivity depends on thedegree of hydration of the micelles in both thesystems. Temperature dependence of DCconductivity in these systems is similar to thatof the reported degree of hydration of the

micelles studiedthrough lightscatteringstudies in boththe systems.

Other researchbyVijayaraghavan,in collaborationwith AshokKumar, includedmagneticsusceptibilitystudies onphospholipidvesicles andbicelles.Phospholipids inwater formmultilamellarvesicles and amixture of long-chain and short-chain

59

phospholipids in water form disc-like micelles orbicelles on appropriate conditions. Massdiamagnetic susceptibility studies wereundertaken on the pure DPPC/water andDMPC/water systems with the addition ofvarious concentrations of cholesterol. In theabsence of cholesterol, the temperaturedependence of susceptibility for both thesystems exhibits a sharp peak at the gel-to-liquid crystalline phase transition temperature.These peaks broaden and disappear onincreasing the cholesterol concentration. It wasfound that the susceptibility of the ternarysystem markedly depends on the cholesterolconcentration. Temperature dependence ofmass diamagnetic susceptibility studies on theDMPC/DHPC/water systems were alsoconducted for various concentrations of theconstituents. Marked discontinuous changes atthe reported phase transition temperatures forthese systems were found. Vijayaraghavan andKumar related the temperature dependentsusceptibility variations to that of the shapeanisotropy of the bicelles.

Pramod PullarPramod PullarPramod PullarPramod PullarPramod Pullarkkkkkatatatatat’s research interests lie in theareas of biophysics in cell dynamics,locomotion, cell cytoskeleton, transport anddynamics in axons.

During the past year, Pullarkat continued hiswork probing the mechanical properties ofaxons and other soft materials under extension.This research was in collaboration with PhDstudent Seshagiri Rao, Chirag Kalelkar from MIT(USA) and Ashish Lele of National ChemicalLaboratories in Pune. An optical fibre basedforce measurement device was used to probethe viscoelastic properties of polymer melts andreconstituted silk. The setup was completedwith the addition of a feedback loop toindependently control force and extension and aquadrant photodiode for high sensitivity (nano-meter) high speed (tens of kilo-hertz)measurements.

New applications for the force setup were foundand experiments to probe polymer melts underextensional flow were performed. Suchmeasurements are critical in understandingmaterial properties during fibre extrusion. Thenovelty of the setup is in the filament diametersit can probe – thin filaments with only a fewtens of microns in diameter can be studiedusing microscopic amounts of sample. Usingthis technique, Pullarkat and his collaboratorsmade systematic measurements in PDMS of atest material. Preliminary tests were alsoperformed on reconstituted silk. The data isbeing analysed.

Pullarkat and his collaborators made progressin probing active suspensions by monitoring thefibre fluctuations in bacterial suspensions.Swimming E-coli bacteria produce forces ofabout a pico Newton, large enough to besensed by the optical fibre setup. Statisticalanalysis of the fluctuations revealed significantdeviations from pure brownian dynamics, andthe nature of these deviations depends on thetype of motion the particular strand of bacteriaexhibit (tumbling vs. running). They comparedthe fluctuation data with brownian dynamics ofa free tracer particle in bacterial suspension.These experiments reveal super-diffusiveregimes which are of interest. The next steps forthe research include tests on axonal mechanics.

Along with Anagha Datar and Roli Srivastava ofRRI and Aurnab Ghose of IISER, Pune, Pullarkatcontinued with experiments to quantify thebeading process (also known as pearlinginstability) in axons of tissue-cultured neuronalcells. They have now acquired the ability tofluorescently label specific cytoskeletalcomponents. They first developedimmunofluorescence techniques (using primaryand secondary antibodies) to label the differentcytoskeletal filaments and to follow changes intheir distribution during beading. Subsequentlythey started genetically modifying live primaryneurons to make them express fluorescentproteins of interest to enable live cell imaging.

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They carried out a number of quantitativeexperiments, some using new techniques, andare currently analysing the data. They have alsoinitiated a collaboration with colleagues atInstitute Curie to develop theoretical models forthe beading or pearling instability based on theexperimental findings.

During the year, Pullarkat also studied patternformation in differentiating stem cells. Stem celldifferentiation into specialised cell types can bemoderated by controlling the stiffness of thesubstrate they grow on. The mechanismresponsible for this stiffness sensitivity is notunderstood. One line of thought relates changesin the geometry of cell nucleus to its geneexpression profile. Pullarkat performed a seriesof experiments (with quantitative results) aimedat understanding the relation between cellspreading and nuclear geometry in stem cells.He was able to show that the stress on thenucleus is related to the extent of spreadingand is independent of the mode by which cellspreading is regulated. This points to a simplemechanical relationship that is being studied ingreater depth. Characterisation of thesubstrates with gradient stiffness, preparedwith a home-developed setup, is underway. Thisresearch was in tandem with Renu Vishavkarmaof RRI and Jyotsna Dhawan of INSTEM,Bangalore.

R PratibhaR PratibhaR PratibhaR PratibhaR Pratibha’s research interests lie in the field ofliquid crystals, specifically their nanocomposites.

During the past year, she studied strain glassanalogue in a bent-core liquid crystal exhibitingthe dark conglomerate phase. Vitrified statesformed from the dark conglomerate (DC) liquidcrystalline phase, exhibited by two members ofa homologous series derived from 2,7-dihydroxynapthalene made of bent-coremolecules, were characterised using a variety ofexperimental techniques like opticalmicroscopy, differential scanning calorimetry

(DSC), x-ray diffraction (XRD), electro-opticstudies, dielectric spectroscopy and atomicforce microscopy. The results show that twodifferent types of vitrified states are formeddepending on the cooling procedure.

One of them, obtained on gradual cooling fromthe DC phase, exhibits glassy features that havestructural similarity with the DC phase asevidenced by XRD and optical studies and anon-Debye behaviour with one of the dielectricrelaxation modes satisfying the Vogel-Fulcher-Tamman (VFT) relation. However, this vitrifiedstate is of fragile nature and unstable againstcrystallisation over time. On the other hand, thevitrified state obtained by direct quenching ofthe DC phase to room temperature results instronger glass formation.

The difference between these two types ofvitrified states has been explained invoking thebasic structure of the DC phase. It is now wellestablished that the DC phase is characterisedby focal conic domains (FCDs) with negativeGaussian curvature along with saddle splaylayer deformation and absence of long rangeordering. Pratibha proposed that a randomdistribution of the FCDs can create randomlocal strains, resulting in disorder on a longerlength scale, making the DC phase somewhatsimilar to unfrozen strain glass. In such a case,a gradual lowering of the temperature cancause the FCDs, and hence the local strains, tobecome locally ordered resulting in a transitioninto the X phase, which is a form of vitrifiedstate similar to strain glass. However when thesample is suddenly quenched from the DCphase to room temperature, the time requiredfor rearrangement of the FCDs, and thereforethe local strains, is not sufficient and thedisorder present on the longer length scale getsfrozen, resulting in a more stable vitrified state.

Pratibha put forth experimental evidence forlowest symmetry achiral smectic liquidcrystalline phases in compounds made of bent-core hockey stick shaped molecules. Thegeneralised smectic phase (SmCG) proposed by

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de Gennes corresponds to a tilted lamellarphase of fluid biaxial layers. In such a phase,macroscopic tensorial quantities like thedielectric and diamagnetic susceptibility areneither orthogonal nor parallel to the layerplanes. Such systems possess only inversionsymmetry and belong to the triclinic Cisymmetry class. However, if the moleculesconstituting the smectic phase have a bentshape, spontaneous polar order becomespossible, the inversion symmetry is removed

and the system becomes chiral and belongs tothe symmetry class C1 of the lowest symmetryfluids. Experimental studies have been carriedout on a compound composed of bent-corehockey stick shaped molecules and have foundthe occurrence of two new types of smecticphases. Optical, X-ray, dielectric and electro-optic studies show that these smectic phaseshave triclinic Ci point symmetry of the layers.This has been attributed to a special type ofintercalated packing that is possible because ofthe shape of the molecules forming thecompound. These smectic phases are the firstexamples of lowest symmetry achiral liquidcrystalline phases.

Composites materials composed of liquidcrystals and nanomaterials are beinginvestigated intensely because of the prospectof obtaining interesting and improved materialproperties for practical applications. Pratibhacontinued her work in this field withinvestigations of the combination of zinc oxide(ZnO) nanoparticles and a discotic liquid crystal.ZnO nanoparticles possess special propertieslike luminescence, high electron mobility andoptical transparency. They are of interest

because of theirpossible use in lightemitting diodes, fieldeffect transistors andsolar cells. On theother hand, discoticliquid crystals whichform columnarstructures are knownto have applicationsas one-dimensionalconductors and inlight emitting diodesand photovoltaicsolar cells. Theinsertion of ZnOnanoparticles intothe columnar matrixcan therefore lead to

novel functional materials. Pratibha has beencarrying out experimental investigations oncomposites of a discotic liquid crystal and ZnOnanoparticles and has evidence for increasedstability of the columnar matrix and animproved stacking of the discs within thecolumns. Such a stacking can aid in providingan efficient path of electrons and holes alongthe column axis resulting in high conductivity.

During the past year, Pratibha undertookstudies on switchable columnar phases toinvestigate in detail switching mechanisms andthe related structural changes. Thespontaneous polarisation present in columnarphases exhibited by bent-core molecules can

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either be perpendicular or parallel to thecolumn axis. Liquid crystalline phasespertaining to the former and latter types aredesignated as the B1 phase with a non-centredunit cell and the B1rev phase with a centredunit cell, respectively. Further, in the B1revphases the molecules can be either non-tiltedor tilted. Unlike in the B1 phase, spontaneouspolarisation in the B1rev phases can bereoriented by an external field. The mechanismof switching in polar columnar phases made ofbent-core molecules can be quite complex as itinvolves a collective rotation around themolecular long axes in the non-tilted versionand a competition between collective rotationaround the molecular long axes and rotationaround the tilt cone in the tilted versions.

Ranjini BandyRanjini BandyRanjini BandyRanjini BandyRanjini Bandyopadhopadhopadhopadhopadhyyyyyaaaaayyyyy’s areas of professionalresearch interest include structure, dynamicsand rheology of non-Newtonian fluids; ageingand soft glassy rheology; flow-structurecorrelations in complex fluids; targeted drugdelivery; interfacial instabilities; sedimentationof colloidal suspensions and the physics ofgranular media.

During the year gone by, Bandyopadhyaystudied the rise of an intruder in a quasi 2Dgranular bed. A single large intruder embeddedat the bottom of a vertically and sinusoidallyvibrated quasi two-dimensional rectangular cellpacked with mustard seeds rises to the top. Fora range of relative density ratios, intruder sizesand bed heights, the intruder rise time,measured at several angular frequencies andpeak-to-peak amplitudes, varies as a function ofthese parameters as well as the criticalvibration velocity (vc) for the onset of convectivemotion of the mustard seeds. The velocity ofconvection of the mustard seeds at the walls isindependently estimated using high speeddigital video tracking and is found to be in verygood agreement with the values of vc obtainedearlier. These experiments prove unambiguouslythat boundary-driven granular convection is

responsible for the rise of the intruder in quasitwo dimensions and that the peak-to-peakvelocity of shaking, rather than the peak-to-peak acceleration, is the relevant parameter fordescribing the results. This study was done incollaboration with Prakhyat Hejmady, SanjibSabhapandit and Abhishek Dhar.

Research was continued on the cagingdynamics in colloidal glasses of laponite incollaboration with Debasish Saha of RRI andRama Govindarajan of JNCASR. The glassy stateis an out-of-equilibrium, disordered state ofmatter that originates due to the jamming orfreezing of the constituents comprising thesystem. Colloidal glasses are soft glasses (theirshear modulus is much lower than that of hardglasses) and exhibit all the properties typicallyexpected in hard glassy materials – jamming,disorder and non-equilibrium ageing behaviour.“Ageing” is a phenomenon in the glassy statewherein the motion of the constituents appearsto be arrested and the dynamics of the systemcontinues to slow down with time. In this study,Bandyopadhyay and her collaboratorsaddressed the various issues regarding glassformation in the context of ageing colloidalsuspensions prepared by dissolving a glassformer (laponite – a synthetic hectorite clay) inhighly deionised water. In colloidal glasses, theconstituent particles or clusters are trapped incages formed by their neighbours, whichrestricts their motion and slows down theirdynamics. Such caging dynamics, whose timescales are typically expected to be 1-100 µs,were studied by Dynamic Light Scattering (DLS)experiments. The intensity autocorrelationfunction (ACF) exhibited by a glassy laponitesuspension has a stretched exponential formdue to the presence of competing relaxationrates in the system. The origin of this non-exponential decay in ageing colloidal glasseswas investigated in systematic experiments.Further study will include detailed investigationof the length scale-dependence of the fragilityof the colloidal glasses as well as the possibility

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of a gel-like microstructure of laponitesuspensions in salt-free conditions.

Block copolymers such as F127 find importantuses in diverse industrial and technicalapplications and as novel agents in drug andgene delivery applications. Bandyopadhyay andRajib Basak studied the changes in F127micellar morphology on the inclusion of thepainkiller drug ibuprofen (IBF) in thehydrophobic core. They used Dynamic LightScattering (DLS) to estimate the changes in thesizes and critical micellisation temperatures(CMTs) of F127 micelles when IBF isencapsulated in the hydrophobic micellar core.Thus far, they have succeeded in encapsulatingup to 1g/cc IBF in a 0.5 wt.% F127 micellarsolution and DLS experiments have beencompleted on several F127 samples withencapsulated ibuprofen. Analysis of the datashows that the F127 micelles becomeincreasingly compact on the inclusion of IBF.This is attributed to the increase in thehydrophobicity of the micellar aggregate uponincorporation of IBF. It was also found that thesample CMT decreases on the inclusion of IBF,confirming previous results that micellisation ofF127 copolymers is accelerated in the presenceof IBF.

Investigations continued into the physics behindpattern formation at the quasi 2D interfacebetween a Newtonian fluid (such as water) andan ageing non-Newtonian fluid (such as anaqueous suspension of laponite). The injectionof a low viscosity fluid into a more viscous fluidresults in the Saffmann Taylor fingeringinstability. These finger patterns are ubiquitousin technological applications, such as in thepercolation of oil in porous rocks, andunderstanding them is important. Laponite isfirst injected through the central hole of a radialHele-Shaw cell and allowed to age for a pre-determined time. Next, the dyed Newtonianfluids (water and CCl4 are both used to checkthe role of fluid miscibility on the fingeringinstability patterns) are injected in separateexperiments, and the patterns that form due tointerfacial instabilities are recorded by a digitalcamera. It is found that the fractal dimensionsof the patterns change significantly as the ageof the Laponite suspension changes. Saha,Hejmady and Govindarajan have alsocontributed to this research.

Basak and Bandyopadhyay worked onestimating the variations in the yield stressesand the critical shear rates for thickening andbanding phenomena observed in cornstarch

suspensions withchanges in itsconcentration. Thelight scatteringpatterns are beinganalysed usingMatlab to extract I(q)vs. q (where I(q) isthe intensity at awavevector q), theanisotropy of thepatterns and theirorientation angles.The dependence ofrheological data(such as the flowcurve) and creep

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curves on the thickness of the sample cell andtherefore the extent of shear banding is beinginvestigated.

The terminal velocities that a ball attainedduring its fall through laponite suspensions ofvarious ages were estimated during the year,and the effective viscosity of the laponitemedium surrounding the falling ball (i.e. its“microviscosity”) was calculated from a StokesEinstein equation, after incorporatingcorrections for high Reynolds number flows(Re~ 25 for low laponite ages) and wall effects.These microviscosity results were comparedwith rheometric estimates of the zero-shearbulk viscosities of laponite suspensions of thesame ages. It was observed that when the ballfell through laponite suspensions of ages lessthan 4 hours, the calculated microviscosityvalues were much lower than bulk viscosityestimates, implying that the ball rejuvenates theboundary layer surrounding it as it falls throughthese laponite samples. For “older” laponitesuspensions (suspension where age is greaterthan 4 hours), the microviscosity estimates arehigher than the bulk viscosity values.Presumably, this occurs as the repulsiveelectrostatic interactions in the older laponitesuspensions are long-ranged enough that theeffective volume of the laponite clustersreaches the random close packing limit. Thefalling ball therefore struggles to find a pathbetween the laponite particles, which ismanifested as an increase in the microviscosityof the surrounding medium. Bandyopadhyay,along with Debasish Saha and Skanda Vivek ofRRI and Rama Govindarajan of JNCASR,proposed a simple toy model (a PoissonBoltzmann equation for a 1-D array of discs) tounderstand their results in terms of the swellingof laponite clusters due to the percolation ofwater between the layers of laponite particles.

The sedimentation of colloidal gels and glassesof the natural clay bentonite was studied incollaboration with Samim Ali. The sedimentingfront was tracked using a CCD camera and the

sedimentation velocity of the front wascalculated. Three distinct regimes wereunearthed from the sedimentation data: aninitial quiescent regime where there was nosedimentation, followed by a regime of transientcollapse and finally, a logarithmically slowcompaction regime. Additionally, it was foundthat in the transient collapse regime, for largeenough salt concentrations, the sedimentationvelocity increased linearly and then decreasedexponentially. The extents of the three regimeswere found to be sensitive to the method ofsample preparation. The following threemethods were used: salt was added to waterbefore bentonite, salt was added soon after theaddition of bentonite to water and salt wasadded to bentonite suspensions of age sevendays or more to allow the bentonite platelets tofirst delaminate completely. Attempts are beingmade to model the data acquired using aporoelastic model.

Sandeep KSandeep KSandeep KSandeep KSandeep Kumarumarumarumarumar’s research interests cover thedesign, synthesis and applications of variousliquid crystalline materials and understandingthe structure-property relationship in self-assembling supra-molecular architectures.

In the field of liquid crystal nanoscience, hisresearch during the year involved investigatingthe thermo physical properties of liquid crystalnanocomposites, specifically cadmium selenidequantum dots (QDs) dispersed in a discoticliquid crystal columnar matrix. The studiesincluded UV-Vis spectroscopy, photoluminescence spectroscopy, differentialscanning calorimetry, polarising opticalmicroscopy, DC conductivity and small angle X-ray diffraction. This was in collaboration withSagar Laxmi Kishore.

Along with C Kavitha, BS Avinash and VLakshminarayanan, Kumar studied thephotoconductivity of undoped as well asnanostructures of gold chloride doped hexa-alkoxytriphenylene series (HAT4, HAT5 and

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HAT6). It was observed that after doping withgold chloride, the photoconductivity increasedby more than ten times for HAT4 and HAT5 butnot for HAT6. The high photoconductivity can beexplained in terms of the transitiontemperatures, the core-core distances and theirlength of side chains. Photoconductivity of thegold chloride doped hexa-alkoxytriphenylenederivatives was five orders of magnitude higherthan that of undoped compounds. The high NIRabsorbance combined with thephotoconductivity makes this nanocomposite apotential candidate for organic solar cellapplications.

An experimental characterisation ofdispersions of ZnO nanoparticles inthe columnar matrix of a discoticliquid crystal was carried out duringthe year. Thermophysical propertieswere investigated through UV-Visspectroscopy, differential scanningcalorimetry, polarising opticalmicroscopy, dielectricmeasurements, ac and dcconductivity and X-ray diffraction.The experimental results showedthat the inclusion of ZnOnanoparticles into the columnarmatrix enhanced the order of thematrix and did not affect the twodimensional hexagonal lattice. Thereal and imaginary parts of thepermittivity increase by a smallamount in the dispersions and anew loss process appears in theisotropic phase. This study was incollaboration with R Pratibha,Supreet and KK Raina.

As part of designing andsynthesising new liquid crystallinematerials, Kumar and Satyam KumarGupta constructed a novel discoticcore by fusing an imidazole unit witha well-known triphenylene discoticcore. Two new imidazole fused

unsymmetrically substituted triphenylenederivatives were prepared and characterised.While the molecular structures of the newcompounds were verified by 1H NMR, UV, MSand elemental analysis, their liquid crystallineproperties were determined by polarising opticalmicroscopy, differential scanning calorimetryand X-ray diffraction studies. Thesetriphenylenoimidazole derivatives were found toexhibit hexagonal columnar mesomorphismover a wide temperature range.

In collaboration with AK Prajapati of Universityof Baroda, Kumar studied H-shaped liquidcrystalline compounds. Two mesogenic

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homologous series of H-shaped symmetricaldimers were synthesised and their thermotropicproperties studied by differential scanningcalorimetry and on a hot-stage of a polarisingmicroscope. These compounds consisted of twomesogenic units of azoester interconnectedthrough tetramethylene flexible spacers by etherlinkage resulting in the structure of “H-shaped”dimeric compounds. The difference betweenthe two series was in the structure of terminalsubstituents (–CH3 for series I and –OCH3 forseries II) attached on the azoester mesogens atone terminus. All these compounds were foundto be smectogenic. The mesomorphic propertiesof the series were compared with each otherand with other structurally related mesogenic H-shaped dimers. The trans-azobenzene groups ofthe H-shaped dimeric compounds displayed ahigh-intensity ð–ð* transition at about 365 nmand a low intensity ð–ð* transition at around470 nm. Thus photochromism can be achievedby the introduction of the azo linkage to the H-shaped dimeric compounds.

Kumar conducted physical studies on liquidcrystalline materials along with ADL Chandania,Atsuo Fukudaa and Jagdish K Vij. Severalcompounds have been prepared at RRI forvarious physical studies. In a binary mixturesystem of ferroelectric and antiferroelectricliquid crystals whose major component showedan unusual reversed phase sequence ofSmC*A(1/2) – SmC*, a new phase withferrielectric order of five layers was discoveredby the electric field-induced birefringence (EFIB)measurements. The EFIB was measured using aphoto-elastic modulator (PEM) set-up and byapplying an in-plane electric field to ahomeotropic aligned cell filled with the binarymixtures of compounds with ferroelectric andantiferroelectric compounds. The contours ofconstant birefringence in the electric field–temperature (E–T) phase diagrams clearlyindicate a distinct region corresponding to anew phase bordering the four-layer SmC*(1/2)on the low temperature side and SmC*á on thehigh temperature side. This new phase is

unambiguously assigned to SmC*(3/5) whosestructure was calculated by Osipov andGorkunov.

TN RTN RTN RTN RTN Ruckmongathanuckmongathanuckmongathanuckmongathanuckmongathan’s areas of currentprofessional research interests lie in the field ofsoft condensed matter in general and displaysin particular.

During the year gone by, his research was onlow power projection displays. Digital Micro-mirror Devices (DMD) are opticalsemiconductors that are used in digital lightprocessor (DLP) based projectors. DMD has atwo-dimensional array of tiny mirrors that reflectlight from light source(s) on to the screen oraway from it to project images on the screen.DMD is an efficient light modulator and about60% of the light incident on DMD is utilised.Each mirror is of size 12 x 12 µm and operatesin bi-stable mode. Micro-mirrors can switchwithin two microseconds and have a longoperational life of 1012 operations without anyvisible sign of ageing. DMD-based projectorsuse pulse width modulation to display 8-10 bitsof gray shades. The number of time intervals todisplay is 255 and 1,023 to display 256 and1,024 gray shades, respectively.Ruckmongathan proposed a micro-pulse widthmodulation method to displaying gray scalesand achieving a drastic reduction in the numberof time intervals. Gray scale bits are split toform a few groups of bits, each consisting of afew (2-4) bits and using intensity modulation todisplay large number of gray scales. Forexample, eight bits of gray scale can be splitinto 2 four bits to reduce the number of timeintervals to 30 as compared to 255 of pulsewidth modulation. Intensity of the light source isreduced by a factor 16 for the least significantfour bits as compared intensity of light sourcefor the most significant four bits to achieveabout 88% reduction in the number of timeintervals to display 256 gray scales with micropulse width modulation. About 20%-50%reduction in power consumption of light sources

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(that illuminate the DMD) is achieved byselectively switching OFF the light sources thatilluminate large clusters of OFF pixels in framesthat are projected sequentially based on micropulse width modulation.

V LakshminaraV LakshminaraV LakshminaraV LakshminaraV Lakshminarayyyyyanananananananananan’s research interestsinclude electrochemical studies of surfaces andinterfaces formed by self-assembledmonolayers and other organic thin films;electron transfer processes in bio-molecules onelectrode surfaces; electrochemistry in lyotropicliquid crystalline systems; electrical conductivityof doped discotic liquid crystalline systems andconducting polymer nanostructures.

During the past year, Lakshminarayananconducted experiments that demonstrated thatbovine milk can act as a stable electrolyticmedium with surprisingly reproduciblecharacteristics by a study of electrochemicalbehaviour. Various minerals in bovine milk suchas calcium, potassium, magnesium, etc., in freeform provide sufficient ionic conductivity for thispurpose. The electron transfer properties ofthree different redox systems in bovinehomogenised whole milk, skimmed milk andreconstituted milk powder have been studied by

cyclic voltammetryand impedancespectroscopy usinga three-electrodesystem with a golddisc workingelectrode, aplatinum sheetcounter electrodeand a standardcalomel referenceelectrode. It hasbeen shown thatthe milk sustainsthe redox reactionsin the absence of asupportingelectrolyte and the

electrochemical responses are comparable tothose obtained when the same reactions werecarried out in standard solvent preparationscontaining supporting electrolytes. The studydemonstrates the potential of developing newinnovative techniques based on the intricateconcepts of electrochemistry to study variousaspects of milk that may help in thedevelopment of analytical sensors for the diaryindustry. This study was done in collaborationwith VSP student K Shrikrishnan.

Electrochemical reactions of ferrocene are aquintessential reversible redox system studiedin non-aqueous systems. This is also a systemin which the redox species is present in theneutral state in reduced form and in positivelycharged state in the oxidised form. This makesthe system a fascinating example of transitionfrom neutral to charged form andsimultaneously from hydrophobic to hydrophilicstates. This prompted Lakshminarayanan andPhD student Anu Renjith to undertake extensivestudies on the redox behaviour of the systems.Electrochemical studies carried out withdifferent ferrocene derivatives dissolved indifferent solvents showed that the half peakpotentials depend on the dielectric constant of

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the medium which has been rationalised interms of the stability of the species in themedium. Studies were also carried out on theeffect of electron withdrawing/donatingsubstitution on the half peak potentials. Thevariations in the half peak potentials have beeninterpreted in terms of the rate of chargetransfer phenomenon at the interface.

The electron mediating properties of thesurface films are important in the developmentof biosensors and studies of biological electrontransfer processes. In this connection, theferrocene thiol self-assembled monolayer lendsitself as a possible candidate for interestingstudies as electron mediator due to the fact thatit has the properties of widely varying in naturein the oxidised and reduced states on thesurface. In this regard, the electron mediatingproperties of ferrocene hexane thiol self-assembled monolayer on gold electrode werestudied. The behaviour during the electrontransfer process was correlated with the natureof the redox properties.

The immobilisation of enzymes and proteins onsurfaces are important in the study of theelectron transfer processes in biologicalsystems and also in the development ofbiosensors. In this regard, Lakshminarayananand Renjith prepared the Langmuir Blodgettfilms of Heme proteins such as Cytochrome-Cand Myoglobin using self-assembledmonolayers of aromatic thiols as substratematerials. They studied their potentialapplication as a hydrogen peroxide sensorwhich is an important reaction product inbiological electron transfer reactions. Similarwork is being continued for the study of otherproteins.

VVVVVA RaghunathanA RaghunathanA RaghunathanA RaghunathanA Raghunathan’s areas of research interest liein amphiphilic systems, membranes, self-assembly and phase behaviour of surfactantpolyelectrolyte complexes.

Raghunathan, along with PhD student Md ArifKamal, studied the effect of two secosteroids,namely cholecalciferol (vitamin D3) and ergo-calciferol (vitamin D2), on the structure andphase behaviour of dipalmitoylphosphatidylcholine (DPPC) membranes, usingX-ray diffraction. Temperature-compositionphase diagrams of both the systems weredetermined from diffraction data from alignedmultilayers at 98% relative humidity. The two-phase diagrams were found to be almostidentical, with the appearance of four distinctmodulated phases as a function of secosteroidconcentration below the main-transition of thelipid. Three of these phases are characterisedby periodic height modulation of the bilayers,whereas the one that occurs at high secosteroidconcentrations has a periodic thicknessmodulation. These results demonstrate theability of these important components ofbiomembranes to modulate membranecurvature and thickness, which are factorsimplicated in the lateral organisation of proteinsin the membrane.

Raghunathan worked on defect-mediatedlamellar-isotropic transition of amphiphilebilayers along with Antara Pal of RRI and GeorgPabst of the Institute of Biophysics andBanosystems Research, Austrian Academy ofSciences, Graz (Austria). A novel isotropic phaseof amphiphile bilayers, characterised by smallaverage inter-bilayer spacing and short-rangepositional correlations, has been observed in anamphiphile-water system. These bilayers form aweakly-swollen lamellar (L) phase over a widerange of water content, which transforms intoan isotropic (Li) phase on heating. Thistransition is not observed in samples withoutexcess water, where the L phase is stable athigher temperatures. Small-angle X-rayscattering and ionic conductivity studies

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indicate that the L-Li transition is driven by theunbinding of edge dislocation loops, which havebeen shown to destroy the quasi-long-rangepositional order of the lamellar phase.Observation of similar behaviour in other bilayerforming systems dominated by attractive inter-bilayer interactions suggests that this isotropicphase is generic to such systems.

With Kamal, Raghunathan studied the influenceof some major phytosterols on the structure andphase behaviour of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine

(POPE) membranes. Phase diagrams of thebinary systems were determined from X-raydiffraction data. All DPPC-phytosterolmembranes studied exhibit a sterol-inducedmodulated phase (P_) below the maintransition, first reported in DPPC-cholesterolmembranes. Structural features of this phasewere deduced from electron density mapscalculated from the diffraction data. In addition,a re-entrant ripple phase was observed inDPPC-stigmasterol membranes as a function oftemperature. The increase in the bilayerthickness in the fluid phase, due to the orderingof the lipid chains by the sterol molecules, was

also determined from the electron densityprofiles of the bilayers. All the phytosterolsstudied were found to increase the bilayerthickness, but to a lower extent compared tocholesterol. Some of the phytosterols phaseseparate from POPE even at very lowconcentrations, whereas the others have asimilar effect on the phase behaviour of POPE,with the temperature range over which the fluidlamellar phase occurs first decreasing and thenincreasing with increasing phytosterolconcentration.

The influence of tocopherols on the structureand phase behaviourof DPPC bilayers wasdetermined from X-ray diffractionstudies on orientedmultilayers. In all thethree cases themain-transitiontemperature (Tm) ofDPPC was found todecrease withincreasing tocopherolconcentration up toaround 25 mol%.Beyond this the maintransition wassuppressed in thecase of tocopherol,

whereas the Tm became insensitive tocomposition in the other two cases. The pre-transition was found to be suppressed over anarrow tocopherol concentration range between7.5 and 10 mol% in DPPC-tocopherol and DPPC-tocopherol bilayers, and the ripple phaseoccurred down to the lowest temperaturestudied. In all three cases, a modulated phasewas observed above a tocopherol concentrationof about 10 mol%, which is similar to the P_phase reported in DPPC-cholesterol bilayers.This phase is found to occur even in excesswater conditions at lower tocopherolconentrations and consists of bilayers with

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periodic height modulation. These resultsindicate the ability of tocopherols to inducelocal curvature in membranes, which could beimportant for some of their biological functions.

Raghunathan and Kamal also studied theinfluence of ring-substituted oxysterols on thephase behaviour of DPPC membranesOxysterols are oxygenated derivatives ofcholesterol that form a class of potentregulatory molecules with diverse biologicalactivity. Given the implications of oxysterols inseveral physiological/pathophysiologicalpathways of human diseases, it is important toidentify how their presence influences thebiophysical properties of cell membranes. Theyfirst described the structure, formation andbiological functions of oxysterols, along withprevious work on the influence of thesemolecules on the structure and phasebehaviour of lipid membranes. They presented

the results of X-ray diffraction experiments onaligned multilayers of DPPC membranescontaining some ring-substituted oxysterols. Theinfluence of these molecules on the phasebehaviour of DPPC membranes is was to bevery similar to that of cholesterol. All theoxysterols studied induced a modulated phasein DPPC membranes, similar to the onereported in DPPC-cholesterol membranes.However, some differences were observed inthe ability of these molecules to suppress themain transition of the lipid and to induce chainordering, which might be related to differencesin their orientation in the bilayer.

YYYYYashodhan Hatwashodhan Hatwashodhan Hatwashodhan Hatwashodhan Hatwalnealnealnealnealne’s current areas ofprofessional interest are phenomenologicaltheory of liquid crystals, membranes andpolymer crystallisation.

During the past year, he conductedexperimental studies on statics and dynamics ofsome novel instabilities in lyotropic systems incollaboration with Tripta Bhatia and NVMadhusudana. New instabilities were observedwhich led to the formation of lamellar tubuleswith a solvent core during dissolution ofamphiphilic molecules in water. The tubulesunderwent a further instability, leading to theformation of beads on these tubules. Usingfluorescence confocal microscopy, the structureof the metastable tubules and beads weremodelled. The stability of the tubular structurewas studied.

Hatwalne studied the detailed structure of theTGBA phase within linear elasticity theory withVenkatramanan PR. They clarified the role andconnection between the geometry, topology andenergetics of this lattice of screw dislocations,which is the analogue of Abrikosov flux lattice insuperconductors. A new modulated phase ofliquid crystals was predicted based upon the co-variant elasticity of smectic-C liquid crystals.This phase is a manifestation of covariance inthe unusual context of achiral smectics. This

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research was in collaboration withVenkatramanan and Madhusudana.

Earlier work on chiral symmetry was extended,in collaboration with Jaya Kumar A and MMuthukumar, to take into account the effect ofline tension in the mechanism for chiralsymmetry breaking in ribbon-like structuresforming spherulites of achiral molecules (suchas polyethylene). Other ongoing work includesthe formulation of elasticity theory of crystallinemembranes and thin plates with topologicaldefects.

Mahesh KMahesh KMahesh KMahesh KMahesh Kumar Vumar Vumar Vumar Vumar Variaariaariaariaaria’s research duringthe year gone by included synthesis ofblue phase forming materials. Hesynthesised two new series having bluephase, but work is going on to completetheir homologues. Stabilising theseblue phases is being attempted withcarbon nano-tube and other materials.During these experiments, an N* phasewas discovered on another newmolecule, which is being studied for itsphysical properties.

Synthesis of the peri-dodecasubstitutedhexabenzenecoronene and peri-hexasubstituted hexabenzenecoronenecompounds are well known and veryinteresting DLCs but their isotropisationtemperature is very high. To lower thistemperature, Varia and hiscollaborators synthesised one final peri-dodecasubstitutedhexabenzenecoronene molecule, whichis still under chemical characterisation.

Truxene is much more interesting fromthe researcher’s point of view becauseof the discotic nematic phases andcurvature on the shape of the molecule.As such, hexamethoxy truxene wassynthesised and work is going onregarding the branched and oxy-

methylene peripheral hexa-substituted truxenevia ether and/or ester linkages.

The rod-disk type rufigallol molecule wassynthesised successively and presented at theInternational Workshop on Soft MatterChemistry in November 2011. It was found tohave nematic as well smectic mesophases;work on rod-disk type triphenylene molecule isunderway.

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THEORETICALPHYSICS

THEORETICALPHYSICS

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O v e r v i e w

Members often engage in collaborations amongeach other and/or groups of the institute thatconduct experimental physics activities. Thegroup has also created a forum for theorists toconduct simple table-top experiments that canexpress conceptual points.

The following pages summarise the major areasof research for the TP group. Each member’sindividual work during the last year is providedin the next section, giving the reader a moredetailed and technical description of theirrespective research activities.

Established in 1995, the Theoretical Physics

(TP) group comprises research faculty, post

doctoral fellows and students who work at the

interface between mathematics and physics.

There are four main areas of research –

statistical physics, soft matter physics

(including physics in biology), gravitation and

the foundations of quantum mechanics. Areas

of interest within statistical mechanics are

mesoscopic physics, non-equilibrium physics,

soft condensed matter physics and biophysics.

Research in general relativity includes

gravitational waves and quantum gravity.

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STATISTICAL MECHANICSWhen a macroscopic device or a sample of bulkmaterial is scaled down to mesoscopic size(from a few microns to the size of a singleatom), they begin to reveal quantum mechanicaleffects. As a result, its properties might be verydifferent from its parent material.

Research in this area is focused on developingtheories for transport of heat and electricityusing the Langevin equation and scatteringapproaches. The role of disorder (includinglocalisation), nonlinearity and dissipation ontransport properties are being investigated.Other areas of interest include the study oflarge deviations and nonequilibrium fluctuationtheorems as well as the statistics of extremeevents. Issues related to the jamming ofgranular matter and onset of shear waves in abacterial bath have been addressed in therealm of nonequilibrium statistical mechanics ofsoft matter. There is also interest inunderstanding the equilibrium and dynamicalproperties of polymers.

Theoretical and experimental research in heatand electron transport in mesoscopic scalesystems is important for the advancement ofthe fundamental understanding of the transportproperties of materials, which in turn would laythe foundation needed to improve theperformance of nanodevice applications andtechnologies.

The development of fast algorithms to estimatethe probability of rare events is part of theongoing research in the field of non-equilibriumstatistical mechanics. Developed in the contextof physics, such algorithms are also importantin other areas of life like finance and cellularprocesses in biology.

BIOLOGICAL PHYSICSVarious topics in the field of biophysics haveattracted the interest of the TP as well as theSCM groups. This field is an example of thevalue of having a relatively small institute with awide range of professional research interestsand scientists who are open-minded and eagerto move into new areas and apply theirexperience to related fields. Recent work inbiological physics includes investigations onvesicle formation and transport, mitochondrialdistribution dynamics, and the physics inexperiments of DNA stretching and twisting.Research in biophysics involves activecollaboration with experimental groups oncampus and at the National Centre forBiological Sciences.

GENERAL RELATIVITYResearch has been undertaken in the precisecalculation of gravitational waveforms expectedfrom inspiralling binaries. This problem is ofcontemporary significance because laserinterferometer gravitational wave detectors likeLIGO and VIRGO have come online andachieved their design sensitivity. However, thesignals are weak and buried in noise, and oneneeds accurate templates with which the datamay be cross-correlated in order to detectgravitational wave signals from astrophysicalsources. Research by the TP group at RRIincludes examining signal detection with futurespace based gravity-wave detectors like LISAand shows that improvements are possible indetection limits with more complete treatmentsof the waveforms. The full waveform leads toimproved angular resolution for super massiveblack hole binaries, and hence data from LISAcan be used to constrain the dark energyequation of state to within a few percent,comparable to the level expected from otherdark energy missions.

Research is also being carried out into physicalapplications of the Ricci flow in general

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relativity. The Ricci flow is a heat equation formetrics, which tends to smooth out geometriesand wipe out memory of the initial conditions.The analogy between the Ricci flow and theapproach of a physical system to thermalequilibrium is being studied to understandblack hole entropy.

QUANTUM GRAVITYAt RRI, research is carried out within twodistinct approaches to quantum gravity. One isLoop Quantum Gravity (LQG), which is anapplication of standard Hamiltonian methods ofquantisation to the classical gravitational fieldwithout recourse to perturbation theory. Inparticular, this requires an understanding ofhow to quantise a field theory in the absence ofa fixed background spacetime. New tools andideas have been developed in LQG to deal withthe absence of a background spatial geometry,while issues related to the absence ofbackground time and recovery of continuumspace-time geometry in the classical limitcontinue to be a frontier area of research. Otherareas of interest are the application of LQGideas to a truncated space of homogeneousand isotropic (cosmological) gravitational fieldsas well as technically simpler generallycovariant toy models.

The other approach is Causal Set Theory, inwhich the space-time continuum is replaced bya discrete substructure that is a locally finitepartially ordered set, the causal set. Thefundamental idea is that finite continuumspace-time volumes in fact contain only a finitenumber of basic space-time elements, relatedto each other by a causal relation. Work oncausal set theory includes investigations intoclassical stochastic growth models, causal settopology, toy models for quantum causal setdynamics and on the construction of aconsistent quantum theory of causal sets.Alongside, investigations have also been carried

out into observer-independent alternativeformulations of quantum theory.

One of the puzzles of cosmology is thesmallness of the cosmological constant, thedark energy that drives the expansion of theuniverse. It has been suggested that theobserved cosmological constant may be due toquantum gravity fluctuations. Pursuing thisidea, an analogy has been made between thecosmological constant and surface tension offluid membranes. The analogy relates esotericquantum gravity effects that are too high inenergy to probe directly to standard physics thatcan be tested in a laboratory. This suggests ananalogue quantum gravity experiment, whichprobes the fluctuating surface tension of micronsized fluid membranes. This is an example ofthe connections that emerge from theinteractions at the institute between differentfields of research.

THEORISTS LABORATORYThis is a forum for theorists to conduct simpletable-top experiments. There have beenexperiments with vibrated grains, theMarangoni effect and studies of Brownianmotion in milk globules. There have beenseveral demonstrations developed using simplematerials such as a rotating cube, anarchimedian screw pump, a low Reynold’snumber effect, and demonstrations involvingsoap films and soap bubbles to expressconceptual points. These serve as an aid toeducation as well as understanding.

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AAAAAbhishek Dharbhishek Dharbhishek Dharbhishek Dharbhishek Dhar’s areas of professional researchinterests include non-equilibrium statisticalmechanics and soft matter physics.

During the year gone by, he, along with PrakhyatHejmady, Ranjini Bandyopadhyay and SanjibSabhapandit, studied new scaling behaviour inboundary-driven granular convection. When aquasi-two-dimensional bed of mustard seeds isvertically vibrated, the formation of convectionrolls in the cell is observed. Convection isobtained only when the side walls of the cell areroughened, which means that convection isboundary-driven. To quantify the observedconvection, the time it takes for a test particle,driven by the flow, to rise from the bottom of thecell to the top was measured. A wide range ofdriving parameters – including amplitude ofvibration (a), frequency of vibration (f) and cellsize – was also measured. It was found that thedata collapsed when plotted as a function ofthe driving velocity (af) as against the acceptedbelief that the parameter controlling convectionis the driving acceleration (af^2).

He also studied the density matrix descriptionof quantum systems in non-equilibrium steadystates. For systems in equilibrium, theprobability of various allowed states of aquantum system kept in contact with a heatbath is given by the Gibbs-Boltzmanndistribution. The density matrix is the canonicaldistribution; if the system is also in contact witha particle reservoir, then the grand-canonicaldistribution is used. However, there is no suchgeneral prescription for specifying the densitymatrix of systems that are out of equilibrium.This research, in collaboration with Keiji Saito ofTokyo University (Japan) and Peter Hanggi of theUniversity of Augsburg (Germany), looked atmodels where a quantum system is connectedto two reservoirs of energy and particles, so asto product current-carrying non-equilibriumstates. A procedure for explicitly finding the non-equilibrium density matrix in these models wasdemonstrated.

O n g o i n gR e s e a r c h

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In collaboration with Venkateshan Kannan andJoel L. Lebowitz of Rutgers University (USA),Dhar researched the non-equilibrium steadystate of a harmonic crystal with alternatingmasses. They analysed the non-equilibriumsteady state of a one-dimensional harmonicchain of N atoms with alternating massesconnected to heat reservoirs at unequaltemperatures. It was found that the temperatureprofile defined through the local kinetic energyoscillated with period two in the bulk of thesystem. The heavier or the lighter particles inthe bulk are hotter depending on boundaryconditions. The explicit integral expressions forthe bulk temperature profile and steady statecurrent in the limit of large N were obtained.

In trying to understand transport properties ofsystems with applied thermal gradients orelectrical fields, the area of interest is not justthe average current flow but also thefluctuations of the current. The currentgenerating function is a quantity that containsinformation on all moments of the current. Itscomputation is a difficult problem. In 2004,Bodineau and Derrida made a remarkableconjecture, namely, the additivity principle,which enables one to compute the fullgenerating function from just the temperaturedependent thermal conductivity of a system. Sofar the conjecture has been proved only for one-dimensional diffusive systems. Saito and Dharstudied heat transport in two- and three-dimensional disordered harmonic crystals andnumerically demonstrated the validity of theconjecture even in these systems.

Along with Anjan Roy and Sanjib Sabhapandit ofRRI and Onuttom Narayan of UC Santa Cruz(USA), Dhar investigated the motion of onesingle marked particle in a gas of interactingparticles kept inside a box, by looking at themean square deviation (MSD) of its position.For a gas of equal mass hard particles, it isknown that there is a diffusive regime and theMSD saturates because of the finite size of thebox. This study is addressing the questions of

whether the diffusive behaviour occursuniversally and of the nature of the approach tothe saturation value. This work is computation-intensive and has extensively used the RRIcluster.

Bala IyBala IyBala IyBala IyBala Iyererererer’s professional research interests lie inthe areas of general relativity and gravitationalwaves. During the year gone by, he was involvedin the computation of the quadrupole mode ofthe gravitational waveform of inspirallingcompact binaries at the third and half post-Newtonian (3.5PN) approximation of generalrelativity. This research was done incollaboration with Guillaume Faye, SylvainMarsat and Luc Blanchet of the Institutd’Astrophysique de Paris (France).

The computation was performed using themulti-polar post-Newtonian formalism, andrestricted to binaries without spins moving onquasi-circular orbits. The new inputs mainlyinclude the 3.5PN terms in the massquadrupole moment of the source and thecontrol of required subdominant corrections tothe contributions of hereditary integrals (tailsand non-linear memory effect). The result wasgiven in the form of the quadrupolar mode in aspin-weighted spherical harmonicdecomposition of the waveform, and will allow amore accurate comparison with the outcome ofnumerical relativity simulations.

Joseph SamuelJoseph SamuelJoseph SamuelJoseph SamuelJoseph Samuel’s areas of professionalinterests are in the use of geometry andtopology in physics, especially geometric phasein quantum mechanics and optics, generalrelativity and DNA elasticity. His recent workrelates to analogies between quantumgravitation and the physics of lipid membraneswhich leads to a relation between surfacetension and the cosmological constant.

During the past year, Samuel continued hisresearch into DNA elasticity, in collaboration

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with Supurna Sinha, to arrive at a clearunderstanding of DNA elasticity using thestandard techniques of statistical mechanics.While experiments do exist, their interpretationrequires special attention because of thegeometric and topological subtleties of theWrithe. This work examines the effect ofthermal fluctuations on the statisticalmechanics of DNA by using the Gelfand-Yaglommethod for computing fluctuation determinants.

With Sinha, Samuel studied whether atominterferometry can be used to accurately testthe Red Shift effect. The study involves criticallyexamining the idea of a clock in generalrelativity. The study leads to a proposal of a newclass of experiments in general relativity whichstudy the interference of quantum clocks.

Samuel – in collaboration with A Martin, OAlibart, JC Flesch and S. Tanzilli from theLaboratoire de Physique de la Matièr Condense,Université Nice (France), and Supurna Sinhaand A Kastberg from RRI – experimentallydemonstrated the geometric phase effect oncoincidence counts of photons. The effect waspredicted in an earlier theoretical paper andconfirmed by this experiment. The experimentsuggests ways of tuning entanglement inquantum optics.

Along with a team from RRI comprising NandanSatapathy, Deepak Pandey, Poonam Mehta,Supurna Sinha and Hema Ramachandran,Samuel demonstrated the existence of a non-local geometric phase in the intensity-intensitycorrelations of classical incoherent light, notseen in the lower order correlation. This two-photon Pancharatnam phase was observed andmodulated in a Mach-Zehnder interferometer.Using acousto-optic interaction, independentphase noise was introduced to light in the twoarms of the interferometer to create twoindependent incoherent classical sources fromlaser light. The experiment is the classicaloptical analogue of the multi-particle Aharanov-Bohm effect.

Samuel presented an analytical closed formexpression that gives a good approximatepropagator for diffusion on the sphere. Theformula is the spherical counterpart of theGaussian propagator for diffusion on the plane.While the analytical formula is derived usingsaddle point methods for short times, it workswell even for intermediate times. This formulagoes beyond conventional “short time heatkernel expansions” in that it is nonperturbativein the spatial coordinate, a feature that is idealfor studying large deviations. This work, done inconjunction with Abhijit Ghosh of the SogangUniversity, Seoul (South Korea), and Sinha,suggested a new and efficient algorithm fornumerical integration of the diffusion equationon a sphere.

MadhaMadhaMadhaMadhaMadhavvvvvan Van Van Van Van Varadarajanaradarajanaradarajanaradarajanaradarajan’s areas of professionalresearch interest are classical and quantumgravity.

During the past year, he worked an anomaly-free quantum dynamics for a weak couplinglimit of Euclidean gravity, in collaboration with CTomlin of Penn State University (USA). The weakcoupling limit of Euclidean gravity introduced bySmolin is described by a generally covariantabelian gauge theory. The Poisson bracketalgebra of its Hamiltonian and diffeomorphismconstraints is isomorphic to that of gravity.Motivated by recent results in ParameterisedField Theory and by the search for an anomaly-free quantum dynamics for Loop QuantumGravity (LQG), the quantum Hamiltonianconstraint of density weight 4/3 for this abeliantheory is constructed so as to produce a non-trivial LQG-type representation of its Poissonbrackets through the following steps. First, theconstraint at finite triangulation, as well as thecommutator between a pair of such constraints,is constructed as operators on the “charge”network basis. Next, the continuum limit of thecommutator is evaluated with respect to anoperator topology defined by a certain space of“vertex smooth” distributions. Finally, the

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operator corresponding to the Poisson bracketbetween a pair of Hamiltonian constraints isconstructed at finite triangulation in such a wayas to generate a “generalised” diffeomorphismand its continuum limit is shown to agree withthat of the commutator between a pair of finitetriangulation Hamiltonian constraints.Varadarajan’s results, in conjunction with therecent work of Henderson, Laddha and Tomlinin a 2+1-dimensional context, constitute thenecessary first steps towards a satisfactorytreatment of the quantum dynamics of thismodel. They also worked on improving theconstructions of the work above so as toincorporate diffeomorphism covariance. Thiswork involved an intricate choice of regulatingcoordinate patches, an application of certainresults on cyclic finite subgroups of the group ofgeneral linear transformations and amodification of the set of vertex smoothfunctions with restricted short distancebehaviour.

Other research by Varadarajan was on theKoslowski-Sahlmann (KS) representation forquantum gravity. The KS representation is anLQG representation with a non-trivial

background spatial geometry. The existence ofhitherto unnoticed, yet crucial, operators whichimplement changes in this background weredemonstrated. Using these operators, errors inthe solutions of the gauge constraints werecorrected. Varadarajan and his collaboratorsaim to use this representation to construct aquantum arena for asymptotically flat gravity infuture work.

N KN KN KN KN Kumarumarumarumarumar’s areas of research interest coverrandomness, dissipation and decoherence incondensed matter, both quantum and classical.

During the past year, his research was focusedmainly on the absence of classical equilibriumorbital (dia) magnetism (the Bohr-van Leeuwen(BvL) Theorem that has been a surprise ofphysics). Work was done in continuingcollaboration/conversation with colleagues(from the TP, AA and LAMP groups) and someVSP students. The stated absence of classicalorbital (dia) magnetism was traced to DetailedBalance (the second fluctuation dissipation, II-FD, theorem due to Kubo – that there are nocycles in equilibrium). As a complement to the

BvL theorem, it wasshown that astochastic-dissipative systemof charged particlescan indeed give anon-zero orbitalmagnetic momentin the classicalsteady-state, andthat the momentcan even beparamagnetic forcertain deviationsfrom the II-FDtheorem. This wasconsistent withKumar’s numericalsimulation for adissipative

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stochastic system driven by the Kubo-Anderson(non-Markovian) process. The positive feedbackpossible due to paramagnetism suggests amechanism for the generation of magneticfields, possibly the seed field in the classicalastrophysical context. Experimental realisationin the laboratory using optical traps and laserpulsing was suggested.

Another area of N Kumar’s research during theyear was the study of propagation of lightthrough a ferrofluid (suspension on ~single-domain nm-scale magnetite particle inkerosene), which scattered dielectrically andwas tuneable magnetically. An experimentalstudy was carried out in RRI’s LAMP Group tomeasure the intensity of forward/backwardscattering and the polarisation of the scatteredlight as a function of the applied transversemagnetic field. These results were qualitative inagreement with the analytical calculationsbased on invariant imbedding for a modelsystem.

Sanjib SabhapanditSanjib SabhapanditSanjib SabhapanditSanjib SabhapanditSanjib Sabhapandit’s research interests covervarious fields of statistical physics, includingstatistical physics of out-of-equilibrium systems,disordered systems, stochastic processes,extreme value statistics, integer partitions,granular media, dynamics of polymers, andlarge deviations of rare events for various non-equilibrium additive processes.

During the past year, Sabhapandit studied thefluctuations of the work done by an externalGaussian random force on a harmonic oscillatorthat is also in contact with a thermal bath. Heobtained the exact large deviation function aswell as the complete asymptotic forms of theprobability density function. The distribution ofthe work done was found to be non-Gaussian.The steady state fluctuation theorem holds onlyif the ratio of the variances of the externalrandom forcing and the thermal noise,respectively, is less than 1/3. On the otherhand, the transient fluctuation theorem holds

(asymptotically) for all the values of that ratio.The theoretical asymptotic forms of theprobability density function were found to be invery good agreement with the numerics as wellas with an experiment.

In collaboration with P Hejmady, RBandyopadhyay and A Dhar, Sabhapanditconducted experiments on granular matter.Granular materials are ubiquitous in nature.They are apparently “the second-mostmanipulated material in industry after water”.Besides its obvious technological importance,granular matter is one of the most interestingexamples of a driven dissipative system.Shaken granular matter exhibits variousinteresting phenomena such as convection,segregation and jamming. A strikingexperimental observation in vibrated granularmaterials is the Brazil-nut effect, where a largeintruder particle immersed in a verticallyshaken bed of smaller particles rises to the top,even when it is much denser. A related effect isthe segregation obtained on vibrating a mixtureof particles of different sizes and densities.Sabhapandit was involved with an experimenton the shaken granular matter, whereinexperimental measurements were taken of therise-time of an intruder in a vertically vibratedquasi-two-dimensional bed of mustard seeds.Very interesting scaling behaviour in the Brazil-nut effect was observed over a wide range ofshaking frequencies and amplitudes.

Sumati SurSumati SurSumati SurSumati SurSumati Suryyyyya a a a a works on both classical andquantum aspects of gravity. The main focus ofher research is on the causal set approach toquantum gravity. In this approach, the space-time continuum is replaced by a discretesubstructure, the causal set, which is a locallyfinite poset. She is also interested in the relatedquestion of quantum interpretation in thecontext of quantum cosmology.

During the year gone by, Surya studied theemergence of the continuum in 2D causal set

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quantumgravity. Theanalysis oftwo-dimensionalmodels ofcausal setquantumgravity wasdone usingnumericalMarkovChainMonte Carlomethodssuite ofnumericalalgorithmsconstructed using the Cactus framework. It wasshown that this simplified model of causal setquantum gravity overcomes many of the hurdlespresent in the general case. In particular, it wasshown to be computationally erdogic and totherefore thermalise rapidly. Several tests werecarried out to establish the stability of the codeand the ergodicity of the Markov process.Recent progress indicates the existence of anew layered quantum gravity phase, andinvestigations are continuing to confirm this.

In tackling the question of full causal setquantum gravity in four dimensions, one dealswith an unrestricted sample space of causalsets. This space is known to be dominated bycausal sets which are nothing like space-time,and one of the big questions in CST is whetherthis entropy can be tamed by a suitabledynamics. In earlier studies of the 4D case, itwas found that the Markov chain was getting“stuck” in these entropically dominantconfigurations for very long simulation times.This is also related to the high rate of rejectionfor the particular choice of Markov chain movethat was used. Using slightly modified movesdid not seem to make a significant difference inthese results. Recently, however, a way around

this was foundby replacingthe samplespace ofcausal sets bya matrixrepresentationwhich allowsfor a far moreefficient set ofIsing-likemoves. Thepreliminaryresults are verypromising andthe hope is touse these toexplore various

aspects of full 4d causal set quantum gravity.This study was in collaboration with DavidRideout of the University of California San Diego(USA) and Rafael Sorkin of the PerimeterInstitute.

Supurna SinhaSupurna SinhaSupurna SinhaSupurna SinhaSupurna Sinha’s areas of current professionalresearch interest are statistical mechanics inparticular and theoretical physics in general.

During the year gone by, she worked on atominterferometers and the gravitational redshift incollaboration with Joseph Samuel. Muller,Peters and Chu (MPC) claim that areinterpretation of decade-old experiments withatom interferometers leads to a sensitive test ofthe gravitational redshift effect. This claim hasbeen disputed by Wolf et al, who adducearguments to show that MPC’s claim isincorrect. In Sinha’s study, this argument hasbeen reduced to a single fundamentalobjection. It was shown that atominterferometric experiments conducted to datedo not test the gravitational redshift effect witha sensitivity determined by the Comptonfrequency of atomic masses. The analysis isgeneral and focuses on points of principlerather than on the present state of

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technological possibility. It is then observed thatit is in principle possible to use atom lasers toproduce sensitive tests of the redshift effect atthe Compton frequency. Such tests may becometechnologically realisable in the future.

An experimental study of the non-localgeometric phase in Hanbury Brown-Twisspolarised intensity interferometry was alsocarried out during the year. The experimentinvolved two independent, polarised, incoherentsources, illuminating two polarised detectors.Varying the relative polarisation angle betweenthe detectors introduced a geometric phaseequal to half the solid angle on the Poincaresphere traced out by a pair of single photons.Local measurements at either detector do notreveal the effect of the geometric phase, whichappeared only in the coincidence countsbetween the two detectors, showing a genuinelynon-local effect. It was shown experimentallythat coincidence rates of photon arrival times atseparated detectors can be controlled by thetwo photon geometric phase. This effect can beused to manipulate and control photonicentanglement. This study was carried out incollaboration with A Martin, O Alibart, JC Flesch,S Tanzilli and A Kastberg of Laboratoire dePhysique de la Matiere Condense, Universite deNice (France) and Joseph Samuel of RRI.

The existence of a non-local geometric phasewas demonstrated in the intensity-intensitycorrelations of classical incoherent light. This isnot seen in the lower order correlation. This two-photon Pancharatnam phase was observed andmodulated in a Mach-Zehnder interferometer.Using acousto-optic interaction, independentphase noise was introduced to light in the twoarms of the interferometer to create twoindependent incoherent classical sources fromlaser light. The experiment is the classicaloptical analogue of the multi-particle Aharanov-Bohm effect. As the trajectory of light over thePoincare sphere introduces a phase shiftobservable only in the intensity-intensitycorrelation, it provides a means of deflecting

the two-photon wavefront, while having noeffect on single photons. Sinha worked withNandan Satapathy, Deepak Pandey, JosephSamuel and Hema Ramachandran of RRI andPoonam Mehta of the Department of Physics,Delhi University.

Along with Joseph Samuel, Sinha carried out ananalytical study of the role of thermalfluctuations in shaping molecular elasticproperties of semiflexible polymers. The studyinterpolates between mechanics and statisticalmechanics in a controlled way and shows howthermal fluctuations modify the elasticproperties of biopolymers. The researchinvolved:

1. A study of the minimum energyconfigurations with explicit expressionsfor their energy and writhe and plots ofthe extension versus Link for theseconfigurations.

2. A study of fluctuations around the localminima of energy and approximateanalytical formulae for the free energy ofstretched twisted polymers.

The central new result of the study is a closedform expression for the leading thermalfluctuation correction to the free energy aroundthe non-perturbative writhing family solution forthe configuration of a biopolymer. From thederived formulae, the predictions of the WormLike Chain (WLC) model for molecular elasticitycan be worked out for comparison againstnumerical simulations and experiments.

Sinha, along with Abhijit Ghosh of theDepartment of Chemical and BiomolecularEngineering, South Korea, and Joseph Samuel,derived an analytical closed form expressionthat gives a good approximate propagator fordiffusion on the sphere. This formula is thespherical counterpart of the Gaussianpropagator for diffusion on the plane. While theanalytical formula was derived using saddlepoint methods for short times, it works welleven for intermediate times. This study suggests

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a new and efficient algorithm for numericalintegration of the diffusion equation on asphere. Monte Carlo simulations wereperformed to compare the numerical efficiencyof the new algorithm with the older Gaussianone.

Post doctoral fellow Sandipan SenguptaSandipan SenguptaSandipan SenguptaSandipan SenguptaSandipan Sengupta’sresearch interests are in the field of guagetheory of gravity and its canonical quantization.

It is well known that the theory of gravity (in fourdimensions) can be written as a SU(2) guagetheory. This involves a canonical description ofgravity in terms of SU(2) guage fields and theirconjugate momenta. In his project, Senguptaand his collaborators attempted to find the mostgeneral SU(2) description of gravity in fourdimensions. It was found that such a frameworkrequired topological deformations in the gravityaction. Possible implications of suchmodifications in the gravity action are currentlyalso under investigation. This study was done incollaboration with Romesh K Kaul of IMSc,Chennai.

RRRRRyuichi Fyuichi Fyuichi Fyuichi Fyuichi Fujitaujitaujitaujitaujita’s professional research interestsinclude gravitational waves and generalrelativity. During the past year, he derivedgravitational waveforms needed to compute the14th post-Newtonian (14PN) order energy fluxfor a particle in circular orbit around aSchwarzschild black hole. This involvedinvestigating the convergence of the energy fluxin the PN expansion and suggesting a fittingformula that could be used to extract unknownhigher order PN coefficients from accuratenumerical data for more general orbits around aKerr black hole. In first order black holeperturbation theory, for extreme mass ratioinspirals which are one of the main targets ofLaser Interferometer Space Antenna, the 14PNexpressions will lead to the data analysisaccuracies comparable to the ones resultingfrom high precision numerical waveforms.

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Laboratories

Radio AstrRadio AstrRadio AstrRadio AstrRadio Astronomonomonomonomonomy Laby Laby Laby Laby LabThe Radio Astronomy Lab (RAL) at RRI consistsof three divisions – Digital Signal Processing(DSP), Millimeter Wave and RF, and X-RayAstronomy.

DSP LabDSP LabDSP LabDSP LabDSP Lab

The DSP lab is involved in the design,development and testing of digital receivers forastronomy. The DSP lab team comprises skilledengineers with expertise in the field of digitalcircuit design and digital signal processing. RRIhas a long history of design and development ofa variety of digital systems (receivers,spectrometers, correlators) that have improvedthe capabilities of national and internationaltelescope facilities. The lab has modern CADdesign packages for the development of FPGA-based digital systems.

MillimeMillimeMillimeMillimeMillimettttter Wer Wer Wer Wer Waaaaavvvvve and RF Labe and RF Labe and RF Labe and RF Labe and RF Lab

The engineers from the RF lab are experiencedprofessionals with diverse skill-sets in thedesign and development of millimeter wave andRF systems. The lab is equipped with allnecessary fabrication and testing facilities forRF systems characterisation. The group hasdesigned and built feeds, broadband antennasas well as standard and special purpose frontend receiver systems operating at wavelengthsfrom decameter to millimeter.

XXXXX-Ra-Ra-Ra-Ra-Ray Astry Astry Astry Astry Astronomonomonomonomonomy Laby Laby Laby Laby Lab

This lab is fully equipped for the developmentand testing of X-ray astronomicalinstrumentation. The infrastructure includes aclean room, X-ray generator, beam line,polariser and monochromator, vacuum systems,mounts and electronics for performanceevaluation of X-ray detectors.

F A C I L I T I E S

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LAMP GrLAMP GrLAMP GrLAMP GrLAMP Group Labsoup Labsoup Labsoup Labsoup LabsEach faculty member of the LAMP group at RRIruns lab facilities specific to his/her individualresearch. These are:

The Laser Cooling, Light Scattering Lab

The Ultrafast and Nonlinear Optics Lab

The Quantum Optics Lab

The Quantum Interactions (QUAINT) Lab

The well-established facilities for laser coolingand trapping of atoms include vacuum systems,commercial and custom-made lasers,spectroscopy equipment, standard electronicsand real time operating systems. The lab thathosts an experimental system to investigatequantum walks of light consists of threeMichelson optical interferometers, variousoptical components and acoustic-opticalmodulator. Two labs allow for experimentalresearch of nonlinear optical properties ofnanocomposites and dynamics, and spectralbehaviour of laser induced plasmas. Standardand custom-made facilities in the lab include afemtosecond laser system with amplifier,nanosecond Nd:YAG laser, spectrometers,monochromators, laser beam profiler, ultra highvacuum chamber, X-ray and gamma raydetectors, experimental set up for z-scan andpump probe measurements, and more.

SCM GrSCM GrSCM GrSCM GrSCM Group Labsoup Labsoup Labsoup Labsoup LabsChemistrChemistrChemistrChemistrChemistry Laby Laby Laby Laby Lab

This lab has state-of-the-art facilities necessaryfor the synthesis and structure characterisationof novel liquid crystal materials. Majorequipment in the lab includes polarising opticalmicroscopes, high performance liquidchromatograph, differential scanningcalorimeter, elemental analyser, infrared andUV-visible spectrophotometer. Over 700mesomorphic molecules have been synthesisedand characterised in the Organic Chemistry Labat RRI.

PhPhPhPhPhysical Measurements Labysical Measurements Labysical Measurements Labysical Measurements Labysical Measurements Lab

The Physical Measurements Lab is equippedwith standard facilities for phase transitionstudies in liquid crystals, liquid crystalnanocomposites and various micellar solutions.The lab members are actively involved in thedevelopment of new precise techniques for avariety of phase transition measurements.Available equipment includes a polarisingoptical microscope, dielectric impedanceanalyser and confocal microscope. Currently,there are experimental set-ups for conoscopic,switching current and various electro-opticalmeasurements.

LiqLiqLiqLiqLiquid Cruid Cruid Cruid Cruid Crystal Displaystal Displaystal Displaystal Displaystal Display Laby Laby Laby Laby Lab

The LCD lab has basic facilities for thefabrication of liquid crystal cells and small size(100mmX100mm) displays as well as standardelectronics equipment for their testing. Spincoating system, vacuum deposition unit,rubbing machine and temperature controlledovens are frequently used by the lab members.

Rheology and Light ScattRheology and Light ScattRheology and Light ScattRheology and Light ScattRheology and Light Scattering Labering Labering Labering Labering Lab

The lab utilises rheology and light scatteringtechniques to study the dynamics of soft glassymaterials and amphiphilic systems. The mostfrequently used instrumentation in the labincludes a dynamic light scatterometer and arheometer. Rheology, dynamic lightscatterometry and diffusing wave spectroscopyare some of the measurement techniques usedin the lab.

XXXXX-Ra-Ra-Ra-Ra-Ray Dify Dify Dify Dify Diffraction Labfraction Labfraction Labfraction Labfraction Lab

The X-ray lab is for investigating the phasebehaviour of various surfactants using X-raydiffraction. Polarising light microscopy andsmall angle X-ray scattering techniques areoften used in the lab. To perform precise X-raymeasurements, the lab is equipped with a

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confocal microscope, X-raydiffractometer and a small angle X-ray scatterometer.

BiophBiophBiophBiophBiophysics Labysics Labysics Labysics Labysics Lab

The Biophysics lab is a self-sufficient lab where various cellscan be grown, manipulated andanalysed. It is equipped with twofully motorised microscopes allowingfor fluorescence and face contrastmicroscopy measurements, confocalmicroscope, biosafety cabinet forgrowing cells, incubators, centrifuge and a 3Dmicroscope for dissections.

ElectrElectrElectrElectrElectrochemistrochemistrochemistrochemistrochemistry and Sury and Sury and Sury and Sury and Surffffface Science Labace Science Labace Science Labace Science Labace Science Lab

The lab performs controlled experiments on testsurfaces in electrochemical cells usingelectrochemical instruments such as apotestiostat, frequency response analyser andlock-in amplifier. An electrochemical quartzcrystal microbalance is used to measure masschanges. Thin film characterisation is done witha variety of scanning probe techniques likescanning tunnelling microscopy, atomic forcemicroscopy and others.

During this year, two major experimentalresearch facilities were set up under the aegisof the SCM group. One is a state-of-the-art FieldEmission Electron Microscope (FESEM) withcryo facilities from Carl Zeiss/Quorum and theother is a Raman spectrograph, both of whichare functioning well.

Mechanical EngineeringMechanical EngineeringMechanical EngineeringMechanical EngineeringMechanical Engineering

The mechanical workshop at RRI meets themechanical design and fabrication needs of RRIexperimental activities. It has the necessarymachinery and a team of skilled personnel whocan undertake fabrication of varioussophisticated mechanical hardware

components for electronics instrumentation aswell as sheet metal work for component,receiver enclosures, and system racks. Theexpertise of the mechanical workshop team hasbeen used in large projects like the fabricationand installation of 1,100 helical antennas forthe Mauritius Radio Telescope, the design andfabrication of a low frequency antenna feedsystem for GMRT, and fabrication of a multi-band feed for the Green Bank Telescope, WestVirginia. Specific tasks such as fabrication ofprecision mounts, positioners and coolingstages for the LAMP and SCM groups have beenundertaken by the mechanical workshop teamas well.

LibraryThe library of RRI was also founded by Sir CVRaman, and ever since, has been a constantsource of both specialised and generalknowledge for its users. Over the years, thelibrary has continuously expanded to keep pacewith the increasing requirement of literature ofthe scientific community of the institute.Currently, the library’s total collection stands at66,713. This collection consists of 26,875books and 39,838 bound volumes of journals.In addition, the library has in its possession1,613 non-book materials that include scientificslides, CD-ROMS, DVDs and audio/video tapes.

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The library continued its partnership in bothFORSA and CSIR-DST National KnowledgeResource Consortium. The current access tousers of the library extends to 17 publishersand their journals of over 4,000. To keep pacewith this increase, the library webpage hasbeen redesigned for easy navigation.

Digital LibrarDigital LibrarDigital LibrarDigital LibrarDigital Library Ay Ay Ay Ay Activitiesctivitiesctivitiesctivitiesctivities

Digitisation of archival materials, which wastaken up in the previous year was continued.146 papers published during this year and 300photographs of Sir CV Raman also wereuploaded in the current year, thus increasingthe number of records to 4,320.

“Imprints Collection” – a bio bibliographicaldatabase of retired scientists of RRI has beendeveloped. At present, 22 scientists and theirresearch work is captured in this database. Thisdatabase provides access to 1,470 researchpapers and 80 PhD theses, in addition to anumber of photographs, lectures (audio/video/text), newspaper clippings and biographicprofiles of individual scientists.

Photo Gallery – a photo exhibition, as anongoing exercise, was initiated on 3 October

2011. Scanning photos of historical importance,digitising them, exhibiting them and thenadding those photos to the digital repositoryhas started. So far, around 300 photos havebeen added using J-album, a free software.

Computer FacilitiesThe various computing needs of differentresearch and development groups and thelibrary at RRI are handled by the computerdivision team. The campus network consists ofa switched gigabit backbone on fibre and wired10/100 Mbps Ethernet to the desktops. Furthermobility is also assured by the secured wirelessnetwork available on the campus premises.

The campus is connected to the internet andthe National Knowledge Network via a highspeed 1 Gbps link. It is also connected to theinternet via a dedicated 10 Mbps link. A 2 Mbpsleased line connects the institute to theobservatory at Gauribidanur. Users are alsoprovided with VPN access to the LAN.

The computing facilities consist of multi-CPUmulti-core systems accessed by users from theirdesktops through a high speed internal LAN.Application-specific software packages along

with developmenttools are availableon these platforms.A cluster of 16nodes, 32 IntelXeon X5570processors, 256GBRAM and 8TBstorage caters tothe heavycomputation needsof users.

The computerfacilities oncampus continuedto be upgraded andimproved during

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the last year. Backup and storage requirementswere addressed to meet increased storageneeds. Operating system and hardwareupgrades were undertaken for key servers, andscientific and other application packages wereprocured and upgraded. The group alsoprovided and managed services such as email,web, printing, VPN and digital repository, amongothers.

CampusThe RRI campus is located in the northern partof Bangalore city. The campus covers an area ofaround 20 acres, where the bustling noise ofthe fast growing metropolis gives way to thesoothing sounds of nature, creating thenecessary peaceful environment for creativework and research. The campus hosts all theoffice buildings, laboratories, a canteen, guesthouse and the 10.4m telescope but whenwalking around, one is left with the impressionthat they are all tiny additions to the prevailingnatural garden.

Most of the campus was landscaped by Sir CVRaman and the RRI Trust is proud to enforcepolicies that protect its unique naturalenvironment. The guest house on campus hasfacilities to comfortably accommodatedistinguished visitors and visiting academics,including visiting doctoral students. A canteen isalso present on campus to provide meals to allguests as well as lunch and refreshments to allRRI employees. Various gatherings, visitor talks,informal meetings, concerts and dinners takeplace at the Village – an ethnically designedarea providing a warm rustic touch to the overallatmosphere on campus.

The building adjacent to the canteen houses asmall clinic where consultant medicalpractitioners pay visits at fixed hours on mostworking days of the week. Sports activities areenvisioned to be an important part of campuslife. Therefore, there are two badminton courtsavailable for use by the research faculty, staffand students. Extensive renovations of majorfacilities and buildings on campus have beentaking place during the last couple of years.

89

PhD ProgrammeRRI offers a PhD programme that givesenthusiastic and motivated students theopportunity to join the global researchcommunity. The unique atmosphere ofintellectual freedom allows the students at RRIto pursue their individual interests within thebroad areas of research conducted at theinstitute. As a result, students are challenged toengage their full creative potential and developthe ability to conduct independent research.Constant formal and informal interactions withthe faculty and other students take the learningprocess outside of the classroom andindividuals’ office space, encouraging studentsto think and question critically others’ and theirown understanding and knowledge. Suchinteractions also promote an open-mindedattitude towards science and research.Attendance on national and internationalconferences exposes RRI students to a much

larger and diverse research community wherethey get a perspective of what the “big picture”in their field of research is.

Students at RRI are registered for a PhD degreewith the Jawaharlal Nehru University, New Delhi.RRI is also a participant in the Joint AstronomyProgramme (JAP) with the Indian Institute ofScience, Bangalore and the Physics in BiologyProgramme with the National Centre forBiological Sciences, Bangalore. Further detailsabout the PhD programme, admissionrequirements and process can be found on thewebsite.

Currently, there are nearly 60 students from allover India enrolled in the PhD programme andconducting research with faculty members fromthe four groups in the institute. Last year sevenPhD degrees were awarded and four weresubmitted for review.

P R O G R A M M E Sacademic

90

Post Doctoral FellowshipProgrammeRRI offers a post doctoral fellowship programmewhich is open for applications throughout theyear. The initial duration of the fellowship is twoyears and is often extended to three. Postdoctoral fellows work independently and havethe academic freedom of choice in researcharea and collaboration. Even though postdoctoral fellows are not required to work in anyspecific research programme or be attached tospecific research staff of the institute, it isdesirable that they have professional researchinterests and a proven track record in areaswith significant overlap or association with theongoing and envisaged activities at theinstitute. Participation of the fellows in theacademic activities of the institute, studentsupervision as co-guides and collaboration withother research staff is encouraged.

Candidates who have already held at least oneposition as a post doctoral researcher can alsoapply for the limited number of PancharatnamFellowships offered at RRI. Applications areaccepted throughout the year and theprocessing time takes between four to sixmonths. The selected candidates are awardedthe PancharatnamFellowship for a period ofthree years. Further detailsabout the post doctoral andPancharatnam fellowships atRRI can be found on thewebsite www.rri.res.in.

Currently, there are 11 postdoctoral fellows at RRI fromthe country and abroad.Their research background,diverse scientific interestsand future goals play animportant role in the overallacademic and researchdynamics of the institute.

Visiting Student Programme(VSP)VSP is aimed at offering research experience tohighly motivated students pursuing theirundergraduate or postgraduate studies. Theduration of the programme varies on a case-by-case basis and can range from anywherebetween six weeks to a whole year. Studentsseeking such opportunities, mainly during theirsummer vacations, also continue to besupported under this programme.

During the period of the visit, the student worksclosely with at least one staff member of theinstitute on a suitable project, or on part of aproject, as appropriate. The student’s work andthe interaction with the staff and other graduatestudents at the institute are expected to provideher/him a flavour of the research pursuits at theinstitute, in general, and a first-hand experiencein research, in particular.

The total number of visiting students at a timeis limited by the availability of projects, mentorsand relevant resources. During the year 2011-2012, a total of 112 students from differentparts of the country participated in theprogramme. The VSP at RRI runs throughout theyear.

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Research Faculty

ASASASASASTRTRTRTRTRONOMY AND ASONOMY AND ASONOMY AND ASONOMY AND ASONOMY AND ASTRTRTRTRTROPHYOPHYOPHYOPHYOPHYSICSSICSSICSSICSSICS

Ravi Subrahmanyan (Director)Research Interests: observational cosmology,extragalactic astronomy, antennas and signalprocessingEmail: rsubrahm@rri.res.in

N Udaya ShankarResearch Interests: sky surveys, detection ofEoR, instrumentation and signal processing forradio astronomyEmail: uday@rri.res.in

Biman NathResearch Interests: cosmology and structureformation, extragalactic astronomyEmail: biman@rri.res.in

AA DeshpandeResearch Interests: neutron stars, pulsars andtransients, instrumentation and signalprocessingEmail: desh@rri.res.in

B RameshResearch Interests: diffuse matter in our andother galaxies, analogue and digital signalprocessing, (sub) millimeterwave telescopesEmail: ramesh@rri.res.in

S SridharResearch Interests: dynamo action due toturbulence in shear flows, MHD turbulence,stellar dynamics in galactic nucleiEmail: ssridhar@rri.res.in

CR Subrahmanya (Visiting Professor)Research Interests: cosmology, extragalacticradio sources, surveys, instrumentation andsignal processingEmail: crs@rri.res.in

Biswajit Paul (Coordinator)Research Interests: X-ray binaries, neutronstars, X-ray instrumentation, data analysisEmail: bpaul@rri.res.in

PEOPLEat RRI

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Shiv Kumar SethiResearch Interests: cosmology and structureformation, reionisation era, cosmologicalmagnetic fieldsEmail: sethi@rri.res.in

KS DwarakanathResearch Interests: extragalactic astronomy,clusters of galaxies, halo and relic radio sourcesEmail: dwaraka@rri.res.in

Lakshmi Saripalli(RRI Trust funded position)Research Interests: morphology and life-cycle ofradio galaxies, surveysEmail: lsaripal@rri.res.in

Nayantara Guptafrom 12.04.2011Research Interests: cosmic rays, neutrinos,gamma rays and gamma ray burstsEmail: nayan@rri.res.in

Harish Vedantham (Research Associate)up to 25.04.2011Research Interests: EoR, radio telescopeinstrumentation, synthesis imagingEmail: harish@rri.res.in

Shashikant (Post Doctoral Fellow)up to 31.10.2011Research Interests: physical cosmology, cosmicbackground radiation, large-scale structure ofthe universeEmail: shashikant@rri.res.in

Siddharth Malu (Post Doctoral Fellow)up to 04.01.2012Research Interests: galaxy clusters, cosmicmicrowave backgroundEmail: siddharth@rri.res.in

Mayuri S (Research Associate)Research Interests: Antenna design for radioastronomy, currently exploring theinstrumentation aspects for X-ray astronomyEmail: mayuris@rri.res.in

Sharanya Sur (Research Associate)from 05.03.2012Research Interests: astrophysical turbulenceand magnetic fields, star formationEmail: ssur@rri.res.in

Harshal Bhadkamkar (Research Associate)from 07.10.2011Research Interests: evolution of X-ray binaries,collective properties of X-ray binaries, binarystar evolutionEmail: harshalhb@rri.res.in

Harsha Raichur (Post Doctoral Fellow)from 05.08.2011Research Interests: X-ray astronomyEmail: harsha@rri.res.in

Nithyanandan T (Pancharatnam Fellow)from 16.05.2011Research Interests: observational cosmology,extragalactic astronomy, dynamic radio sky,statistical methods and modelling in astronomyEmail: t_nithyanandan@rri.res.in

LIGHT AND MALIGHT AND MALIGHT AND MALIGHT AND MALIGHT AND MATTER PHYTTER PHYTTER PHYTTER PHYTTER PHYSICSSICSSICSSICSSICS

Reji PhilipResearch Interests: nonlinear optics, intenselaser field interactions, laser induced plasmasEmail: reji@rri.res.in

Hema RamachandranResearch Interests: quantum computing, lightpropagation in random media, novel opticalapplications of nanomaterialsEmail: hema@rri.res.in

Sadiq Rangwala (Coordinator)Research Interests: ultra cold molecules, iontrapping, atoms and molecules in external fieldsEmail: sarangwala@rri.res.in

Andal NarayananResearch Interests: quantum optics, magneto-optical traps, electromagnetically inducedtransparencyEmail: andal@rri.res.in

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Solomon Ivan (Post Doctoral Fellow)Research Interests: quantum informationtheory, theory of entanglementEmail: solomon@rri.res.in

Urbasi Sinha from 15.03.2012Research Interests: quantum information,quantum computing, quantum optics,superconductivity, nanotechnologyEmail: usinha@rri.res.in

Priya Rose (Post Doctoral Fellow) from26.05.2011Research Interests: ultrafast laser inducedplasma in liquid dropletsEmail: priya@rri.res.in

SOFT CONDENSED MASOFT CONDENSED MASOFT CONDENSED MASOFT CONDENSED MASOFT CONDENSED MATTERTTERTTERTTERTTER

Sandeep Kumar (Coordinator)Research Interests: chemical synthesis of liquidcrystals and their applicationsEmail: skumar@rri.res.in

Raghunathan VAResearch Interests: Amphiphilic systems,membranes, self assembly and phasebehaviour of surfactant polyelectrolytecomplexesEmail: varaghu@rri.res.in

Arun RoyResearch Interests: Phase transitions andelectro-optic properties of liquid crystals,physics of nanomaterials and nanocompositesEmail: aroy@rri.res.in

Pratibha RResearch Interests: liquid crystals,nanocompositesEmail: pratibha@rri.res.in

Lakshminarayanan VResearch Interests: Electrochemistry of surfacesand interfaces, electron transfer processesEmail: narayan@rri.res.in

Ranjini BandyopadhyayResearch Interests: Copolymersurfactantinteractions, drug delivery systems, non-Newtonian flows, gels, soft glasses, granularmediaEmail: ranjini@rri.res.in

Ruckmongathan TNResearch Interests: liquid crystal displays,addressing, controllersEmail: ruck@rri.res.in

Yashodhan HatwalneResearch Interests: phenomenological theory ofliquid crystals, membranes and polymercrystallisationEmail: yhat@rri.res.in

Pramod PullarkatResearch Interests: Biophysics in cell dynamics,cell cytoskeleton, transport and dynamics inaxonsEmail: pramod@rri.res.in

BK Sadashiva (INSA Senior Scientist)Research Interests: chemistry of liquidcrystalline materials, intelligent design andsynthesis of mesogensEmail: sadashiv@rri.res.in

NV Madhusudhana (INSA Senior Scientist)Research Interests: soft condensed matter,liquid crystalsEmail: nvmadhu@rri.res.in

Mahesh Kumar Varia (Post Doctoral Fellow)Research Interests: to synthesise Blue Phaseforming materials and Dodeca-substituted-hexabenzenecoronene discoticsEmail: varia@rri.res.in

Kavitha G up to 31.07.2011Research Interests: structure and phasebehaviour of liquid crystalsEmail: kavitha@rri.res.in

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THEORETICAL PHYTHEORETICAL PHYTHEORETICAL PHYTHEORETICAL PHYTHEORETICAL PHYSICSSICSSICSSICSSICS

Abhishek DharResearch Interests: nonequilibrium statisticalmechanics, soft condensed matter physicsEmail: dabhi@rri.res.in

Sanjib Sabhapandit (Coordinator)Research Interests: statistical physics, extremevalue statisticsEmail: sanjib@rri.res.in

Joseph SamuelResearch Interests: general relativity, optics,soft condensed matter physicsEmail: sam@rri.res.in

Madan RaoResearch Interests: soft condensed matterphysics, physics in biologyEmail: madan@rri.res.in

BR IyerResearch Interests: general relativity,gravitational wavesEmail: bri@rri.res.in

Sumati SuryaResearch Interests: classical and quantumgravityEmail: ssurya@rri.res.in

Madhavan VaradarajanResearch Interests: classical and quantumgravityEmail: madhavan@rri.res.in

N Kumar (Distinguished Emeritus Professor)Research Interests: randomness, dissipation,and decoherence in condensed matterEmail: nkumar@rri.res.in

Supurna SinhaResearch interests: nonequilibrium statisticalmechanics, soft condensed matter physicsEmail: supurna@rri.res.in

Poonam Mehta (Post Doctoral Fellow)up to 31.08.2011Research Interests: neutrino physics andgeometric phaseEmail: poonam@rri.res.in

Roman Sverdlov (Post Doctoral Fellow)up to 05.05.2011Research Interests: quantum gravity, causal settheoryEmail: roman@rri.res.in

Ryuichi Fujita (Post Doctoral Fellow)up to 31.07.2011Research Interests: gravitational waves, generalrelativityEmail: draone@rri.res.in

Samarth Chandra (Post Doctoral Fellow)up to 09.02.2012Research Interests: statistical mechanics, spinglasses, biophysicsEmail: samarth@rri.res.in

Sandipan Sengupta (Post Doctoral Fellow)from 29.11.2011Research Interests: gravitational physics –gauge theoretic formulations of gravity,canonical quantisation of gravity, cosmologyEmail: sandipan@rri.res.in

95

R Somashekarsom@rri.res.in

S Sujathasujathas@rri.res.in

TS Mamathamamatha@rri.res.in

KR Vinodvinod@rri.res.in

KS Srivanivani_4s@rri.res.in

PV Rishinrishinpv@rri.res.in

PS Sasi Kumarsasi@rri.res.in

Light and MattLight and MattLight and MattLight and MattLight and Matter Pher Pher Pher Pher Physicsysicsysicsysicsysics

MS Meenameena@rri.res.in

SofSofSofSofSoft Condensed Mattt Condensed Mattt Condensed Mattt Condensed Mattt Condensed Mattererererer

Mohammed Ishaqishaq@rri.res.in

N Ravi Sankarravisank@rri.res.in

HT Srinivasaseena@rri.res.in

H Subramonyamram_h@rri.res.in

KN Vasudhavasudha@rri.res.in

D Vijayaraghavanvijay@rri.res.in

A Dhasondhas@rri.res.in

Scientific/Technical Staff

Radio AstrRadio AstrRadio AstrRadio AstrRadio Astronomonomonomonomonomy Laby Laby Laby Laby Lab

PG Ananthasubramanianananth@rri.res.in

K Chandrashekara up to 31.07.2011cshekar@rri.res.in

MS Ezhilarasiarasi@rri.res.in

BS Girishbsgiri@rri.res.in

MR Gopala Krishnagkrishna@rri.res.in

PA Kaminikamini@rri.res.in

S Kasturiskasturi@rri.res.in

S Madhavimadhavi@rri.res.in

C Vinuthavinutha@rri.res.in

HN Nagarajanraj@rri.res.in

T Prabuprabu@rri.res.in

KB Raghavendra Raokbrrao@rri.res.in

A Raghunathanraghu@rri.res.in

P Sandhyasandhya@rri.res.in

G Sarabagopalangopal@rri.res.in

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Mechanical Engineering SerMechanical Engineering SerMechanical Engineering SerMechanical Engineering SerMechanical Engineering Servicesvicesvicesvicesvices

V Dhamodharan, In-charge, General Workshop

R Durai Chelvan, In-charge, BasementWorkshop

M AchankunjuI Charles PaulR ElumalaiKO FrancisV Gokula ChandranN GopalM ManiKM MohandasV NagarajanN NarayanaswamyT PuttaswamyD SunandM Suresh Kumar

ComComComComComputputputputputererererersssss

R Nanda Kumar, In-chargenandu@rri.res.in

Jacob Rajanjacobr@rri.res.in

B Sridharsridhar@rri.res.in

S Krishna Murthyskmurthy@rri.res.in

Gauribidanur TGauribidanur TGauribidanur TGauribidanur TGauribidanur Telescopeelescopeelescopeelescopeelescope

HA Aswathappa

PhD Students

AstrAstrAstrAstrAstronomonomonomonomonomy and Astry and Astry and Astry and Astry and Astrophophophophophysicsysicsysicsysicsysics

Peeyush Prasad up to 31.07.2011Research Interests: radio astronomyinstrumentationEmail: peeyush@rri.res.inAdvisor: CR Subrahmanya

Ruta Kale up to 08.04.2011Research Interests: galaxy clusters, magneticfields in intracluster mediumEmail: ruta@rri.res.inAdvisor: KS Dwarakanath

Wasim RajaResearch Interests: neutron stars, pulsars &transients, instrumentation and signalprocessingEmail: wasim@rri.res.inAdvisor: AA Deshpande

Yogesh Maan (JAP student)Research Interests: neutron stars, pulsars &transients, instrumentation and signalprocessingEmail: yogesh@rri.res.inAdvisor: AA Deshpande

Mamta Gulati (JAP student)Research Interests: waves and dynamics indisksEmail: mgulati@rri.res.inAdvisor: S Sridhar

Nishant Kumar Singh (JAP student)Research Interests: astrophysical flowsEmail: nishant@rri.res.inAdvisor: S Sridhar

Kanhaiya Lal PandeyResearch Interests: cosmology and structureformation, reionization eraEmail: kanhaiya@rri.res.inAdvisor: Shiv Sethi

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Nipanjana Patra (JAP student)Research Interests: Cosmology, global 21 cm,EoREmail: nipanjana@rri.res.inAdvisor: Ravi Subrahmanyan

Chandreyee Maitra (JAP student)Research Interests: X-ray polarisation,polarimeter, spectral studies of X-ray binariesEmail: cmaitra@rri.res.inAdvisor: Biswajit Paul

Kshitij Thorat (JAP student)Research Interests: radio astronomy, opticalastronomy, active galactic nucleus evolutionEmail: kshitij@rri.res.inAdvisor: Ravi Subrahmanyan/Lakshmi Saripalli

Mahavir SharmaResearch Interests: cosmology and structureformation, extragalactic astronomyEmail: mahavir@rri.res.inAdvisor: Biman Nath

Lijo Thomas GeorgeResearch Interests: cosmology – BaryonAcoustic OscillationsEmail: lijo@rri.res.inAdvisor: Shiv Sethi

Bharti MehraResearch Interests: X-ray binaries and modellingphenomenon (like bursts) to understand X-raybinariesEmail: bharti@rri.res.inAdvisor: Biswajit Paul

Jagdish Chandra JoshiResearch Interests: quantum chemistryEmail: jagdish@rri.res.inAdvisor: Nayantara Gupta

Nazma Syeda (JAP student)Research Interests: X- ray binaries and X-rayluminosity functions of galaxiesEmail: nazma@rri.res.inAdvisor: Biswajit Paul

Sourabh Paul from 08.07.2011Research Interests: Cosmology, theoreticalastrophysics, MWAEmail: sourabh@rri.res.inAdvisors: Shiv Sethi, KS Dwarakanath, N UdayaShankar

Gayathri Raman from 15.07.2011Research Interests: X-ray astronomy, inparticular analysis of the optical and X-rayproperties of X-ray binaries from the XMM dataarchiveEmail: graman@rri.res.inAdvisor: Biswajit Paul

Gift Jesubalan from 01.07.2011 to 02.05.2012

Light and MattLight and MattLight and MattLight and MattLight and Matter Pher Pher Pher Pher Physicsysicsysicsysicsysics

Seunghyun LeeResearch Interests: Atom-Ion interactionEmail: lee@rri.res.inAdvisor: Sadiq Rangwala

Arijit SharmaResearch Interests: laser cooling of atoms, coldmolecules, optical lattices and BECEmail: arijit@rri.res.inAdvisor: Sadiq Rangwala

Deepak PandeyResearch Interests: laser cooling of atoms,quantum computationEmail: deepak@rri.res.inAdvisor: Hema Ramachandran

Nandan SatapathyResearch Interests: cold atoms, BEC, opticallatticesEmail: nandan@rri.res.inAdvisor: Hema Ramachandran

Ravi KResearch Interests: laser cooling of atoms,trapping of ions, atom-ion interaction, moleculeformation mechanismsEmail: ravi_k@rri.res.inAdvisor: Sadiq Rangwala

98

Jyothi SResearch Interests: quantum interactions ofatoms, molecules and ionsEmail: jyothi@rri.res.inAdvisor: Sadiq Rangwala

Tridib RayResearch Interests: quantum interactions ofatoms, molecules and ionsEmail: tray@rri.res.inAdvisor: Sadiq Rangwala

Karthik HSResearch Interests: foundational aspects ofquantum theory, quantum information theory,open system dynamics, some aspects ofmathematical physicsEmail: karthik@rri.res.inAdvisor: Andal Narayanan

Rahul Sawant Vaijanath from 13.07.2011Research Interests: quantum information,quantum opticsEmail: rahuls@rri.res.inAdvisor: Urbasi Sinha

Muhamed Shafi Ollakkan from 14.07.2011Research Interests: laser produced plasmaspectroscopy and nonlinear opticsEmail: ollakkans@rri.res.inAdvisor: Reji Philip

Buti Suryabrahmam from 15.07.2011Research Interests: quantum opticsEmail: suryabrahmam@rri.res.inAdvisor: Hema Ramachandhran

Amruta Gadge from 15.07.2011Research Interests: cold atoms experiments,Bose-Einstein condensationEmail: amruta@rri.res.inAdvisor: Hema Ramachandran

Madhuri Kumari from 04.07.2011Research Interests: light scattering in randommediaEmail: madhuri@rri.res.inAdvisor: Hema Ramachandran

SofSofSofSofSoft Condensed Mattt Condensed Mattt Condensed Mattt Condensed Mattt Condensed Mattererererer

A JayakumarResearch Interests: theory of liquid crystalsEmail: jkumar@rri.res.inAdvisor: Yashodhan Hatwalne

Radhakrishnan AV up to 31.07.2011Research Interests: amphiphilic systems,surfactantsEmail: avrk@rri.res.inAdvisor: V A Raghunathan

Mohammed Arif Kamal up to 31.07.2011Research Interests: Model membranesEmail: kamal@rri.res.inAdvisor: V A Raghunathan

Antara Pal up to 31.07.2011Email: antara@rri.res.inAdvisor: VA Raghunathan

S RadhikaResearch Interests: liquid crystals,nanocompositesEmail: radhi@rri.res.inAdvisor: R Pratibha

S MadhukarResearch Interests: surfactants, amphiphilicsystemsEmail: madhukar@rri.res.inAdvisor: VA Raghunathan

Rajib BasakResearch Interests: dynamics and rheology ofsoft glassy materialsEmail: rajib@rri.res.inAdvisor: Ranjini Bandyopadhyay

CH Laxmi Kishore SagarResearch Interests: Synthesis of Quantum Dotsand their incorporation into liquid crystals,synthesis of novel liquid crystalsEmail: lksagar@rri.res.inAdvisor: Sandeep Kumar

99

Anu SimonResearch Interests: Electrochemistry of surfacesand interfaces, electron transfer processes ofthin filmsEmail: anu@rri.res.inAdvisor: V Lakshminarayanan

Debasish SahaResearch Interests: Structure and Dynamics ofColloids, Rheology of Soft Glassy Material andFlow Behaviour of Soft SolidsEmail: debasish@rri.res.inAdvisor: Ranjini Bandyopadhyay

Renu VishavkarmaResearch Interests: biophysicsEmail: renuv@rri.res.inAdvisor: Pramod Pullarkat

Santosh GuptaResearch Interests: surfactants, amphiphilicsystemsEmail: santosh@rri.res.inAdvisor: V A Raghunathan

Seshagiri RaoResearch Interests: biophysicsEmail: giri@rri.res.inAdvisor: Pramod Pullarkat

PR VenkatramananResearch Interests: Liquid Crystals, MembranesEmail: venkat@rri.res.inAdvisor: Yashodhan Hatwalne

Tripta Bhatia up to 31.07.2011Research Interests: theory of liquid crystalsEmail: tripta@rri.res.inAdvisor: Yashodhan Hatwalne

Anagha DatarResearch Interests: biophysicsEmail: anagha@rri.res.inAdvisor: Pramod Pullarkat

PK ShabeebResearch Interests: rheology of soft mattersystemsEmail: shabeeb@rri.res.inAdvisor: VA Raghunathan

Avinash BSResearch Interests: electrochemistry of surfacesand interfaces, electron transfer processesEmail: avinash@rri.res.inAdvisor: Sandeep Kumar

Samim AliResearch Interests: rheology of soft mattersystemsEmail: samim@rri.res.inAdvisor: Ranjini Bandyopadhyay

Swamynathan KResearch Interests: chemistry of liquid crystalsEmail: swamynathan@rri.res.inAdvisor: Sandeep Kumar

V Marichandran from 07.07.2011Research Interests: chemistry of liquid crystalsEmail: vmchandru@rri.res.inAdvisor: Sandeep Kumar

RV Jagadeesh from 18.07.2011Research Interests: liquid crystal synthesisEmail: jagadeeshrv@rri.res.in

TheoreTheoreTheoreTheoreTheoretical Phtical Phtical Phtical Phtical Physicsysicsysicsysicsysics

Anirban PolleyResearch Interests: soft condensed matterEmail: anirban@rri.res.inAdvisor: Madan Rao

Chandrakant Mishra (JAP student)Research Interests: gravitational radiation andgeneral relativityEmail: chandra@rri.res.inAdvisor: Bala Iyer

Pragya SrivastavaResearch Interests: biological systems –theoretical studies of active processes in livingcellsEmail: pragya@rri.res.inAdvisor: Madan Rao

100

Anjan RoyResearch Interests: statistical mechanicsEmail: anjanroy@rri.res.inAdvisor: Abhishek Dhar

Chaitra Shreepad HegdeResearch Interests: theoretical physics,statistical mechanicsEmail: hegde@rri.res.inAdvisor: Abhishek Dhar

Prasad VVResearch Interests: theoretical physics,statistical mechanicsEmail: prasadvv@rri.res.inAdvisor: Sanjib Sabhapandit

Suman Gaurab DasResearch Interests: theoretical physics,statistical mechanicsEmail: suman@rri.res.inAdvisor: Abhishek Dhar

Arnab PalResearch Interests: theoretical physics,statistical mechanicsEmail: arnab@rri.res.inAdvisor: Sanjib Sabhapandit

Debdeep Sinha from 25.07.2011Research Interests: causal set approach toquantum gravityEmail: debdeep@rri.res.inAdvisor: Sumati Surya

Visiting Scientists

AstrAstrAstrAstrAstronomonomonomonomonomy and Astry and Astry and Astry and Astry and Astrophophophophophysicsysicsysicsysicsysics

P SreekumarTarun Deep SainiVinod Krishan

Light and MattLight and MattLight and MattLight and MattLight and Matter Pher Pher Pher Pher Physicsysicsysicsysicsysics

R SrikanthR SrinivasanDivya SharmaRavi Gopal VarmaKrishnarai Dastidar

SofSofSofSofSoft Condensed Mattt Condensed Mattt Condensed Mattt Condensed Mattt Condensed Mattererererer

Venkatesh Gopal

TheoreTheoreTheoreTheoreTheoretical Phtical Phtical Phtical Phtical Physicsysicsysicsysicsysics

Janaki Balakrishnan

Radio AstrRadio AstrRadio AstrRadio AstrRadio Astronomonomonomonomonomy Laby Laby Laby Laby Lab

A Krishnan

Adjunct Professors

Ramanath CowsikAnders KastbergRon EkersGirish S AgarwalRafael D Sorkin

101

COUNCIL

Dr K KDr K KDr K KDr K KDr K Kasturiranganasturiranganasturiranganasturiranganasturirangan Member, Planning CommissionChairman

PrPrPrPrProf PK Kof PK Kof PK Kof PK Kof PK Kaaaaawwwww Director, Institute of Plasma ResearchGandhinagar 382 428

Dr T RamasamiDr T RamasamiDr T RamasamiDr T RamasamiDr T Ramasami Secretary, , , , , Department of Science & TechnologyMinistry of Science & TechnologyNew Delhi 110 016

PrPrPrPrProf Raof Raof Raof Raof Ravi Subrahmanvi Subrahmanvi Subrahmanvi Subrahmanvi Subrahmanyyyyyananananan Director, Raman Research InstituteBangalore 560 080 (Ex-officio member)

PrPrPrPrProf O Siddiqiof O Siddiqiof O Siddiqiof O Siddiqiof O Siddiqi National Centre for Biological SciencesTata Institute of Fundamental ResearchBangalore 560 065

Ms Anuradha MitraMs Anuradha MitraMs Anuradha MitraMs Anuradha MitraMs Anuradha Mitra Joint Secretary & Financial AdvisorMinistry of Science & TechnologyGovernment of India, New Delhi 110 016

PrPrPrPrProf AK Soodof AK Soodof AK Soodof AK Soodof AK Sood Physical & Mathematical Sciences DivisionIndian Institute of ScienceBangalore 560 012

PrPrPrPrProf PC Aof PC Aof PC Aof PC Aof PC Agragragragragrawwwwwalalalalal DAE–UM (Dept. of Atomic Energy – Mumbai University)Centre for Excellence in Basic SciencesMumbai University Campus at VidhyanagariHealth Center, Kalina, Santa Cruz (East)Mumbai – 400 098

Finance Committee

Dr K KDr K KDr K KDr K KDr K Kasturiranganasturiranganasturiranganasturiranganasturirangan Member, Planning CommissionChairman

Ms Anuradha MitraMs Anuradha MitraMs Anuradha MitraMs Anuradha MitraMs Anuradha Mitra Joint Secretary & Financial AdvisorMinistry of Science & TechnologyGovernment of India, New Delhi 110 016

PrPrPrPrProf O Siddiqiof O Siddiqiof O Siddiqiof O Siddiqiof O Siddiqi National Centre for Biological SciencesTata Institute of Fundamental ResearchBangalore 560 065

PrPrPrPrProf Raof Raof Raof Raof Ravi Subrahmanvi Subrahmanvi Subrahmanvi Subrahmanvi Subrahmanyyyyyananananan Director, Raman Research InstituteBangalore 560 080

102

Other Staff

AAAAAdministrationdministrationdministrationdministrationdministration

K Krishnama RajuAdministrative Officerkrishna@rri.res.in

K RaghunathaDeputy Administrative Officerkraghu@rri.res.in

Marisa D’Silvamarisa@rri.res.in

K Radhakradha@rri.res.in

SR Ramasubramaniyanram@rri.res.in

V Raveendranravee@rri.res.in

R Ganeshganeshr@rri.res.in

VS Shailajasvs@rri.res.in

G Gayathrigayathrig@rri.res.in

GV Indira

GrGrGrGrGroup Secreoup Secreoup Secreoup Secreoup Secretariestariestariestariestaries

AstrAstrAstrAstrAstronomonomonomonomonomy and Astry and Astry and Astry and Astry and AstrophophophophophysicsysicsysicsysicsysicsVidyamani Vvidya@rri.res.in

SofSofSofSofSoft Condensed Mattt Condensed Mattt Condensed Mattt Condensed Mattt Condensed MatterererererRadhakrishna Kkrk@rri.res.in

Light and MattLight and MattLight and MattLight and MattLight and Matter Pher Pher Pher Pher PhysicsysicsysicsysicsysicsS Harini Kumariharini@rri.res.in

TheoreTheoreTheoreTheoreTheoretical Phtical Phtical Phtical Phtical PhysicsysicsysicsysicsysicsG Manjunathamanju@rri.res.in

RAL LabRAL LabRAL LabRAL LabRAL LabMamatha Bai Rmamta@rri.res.in

AAAAAccountsccountsccountsccountsccountsPV Subramanya, Accounts OfficerV RaghunathR Ramesh, Internal Auditor

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LibrarLibrarLibrarLibrarLibraryyyyyB M Meera, LibrarianS GeethaM ManjunathM N NagarajVrinda J BenegalRaju Varghese, Graphic Arts

SupporSupporSupporSupporSupport Staft Staft Staft Staft StaffffffK ChowdasettyC Elumalai

UUUUUpkpkpkpkpkeepeepeepeepeepHanumanthaJayammaKN KawalappaD KrishnaC LakshmammaT MahadevaT MuraliNarayanaSidde GowdaV Venkatesh

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EstatEstatEstatEstatEstates and Buildingses and Buildingses and Buildingses and Buildingses and BuildingsGB Suresh, Civil EngineerR Sasidharan, SupervisorR Anantha Subba Rao, ConsultantS Anantha RamanK BhoopalanGunashekarC HaridasK PalaniM RajagopalK G NarasimhaluM RameshA RamannaRanjitham

SecuritySecuritySecuritySecuritySecurityCN Ganapathy, In-chargeBM BasavarajaiahUA EarappaH GangaiahKeshavamurthySureshaK KrishnappaMunihobalaiah upto 31.10.2011K PushparajOM RamachandraG RamakrishnaM SannaiahH Vaderappa

ConsultantsConsultantsConsultantsConsultantsConsultantsS Nagaraja

TTTTTransporransporransporransporransportttttCN Ganapathy, In-chargeMK Raju KuttyM BalaramaCK MohananG PrakashRahamath PashaG RajaM Venkateshappa

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HorHorHorHorHorticultureticultureticultureticultureticultureBylappaLingegowdaD MahalingaMailarappaMarappaD MunirajaS MunirajuRahamathulla KhanRangalakshmiVaralakshmi

MedicalMedicalMedicalMedicalMedicalConsultant Paediatrician: Dr MR BaligaConsultant Physician: Dr BV Sanjay RaoTechnician: R Shanthamma

CarCarCarCarCarpentrpentrpentrpentrpentryyyyyM Gopinath

Gauribidanur TGauribidanur TGauribidanur TGauribidanur TGauribidanur Telescope Supporelescope Supporelescope Supporelescope Supporelescope Support Staft Staft Staft Staft StaffffffBheema NaikGangaramM MuniyappaPapannaPrahallada Rao (up to 28.02.2012)RP Ramji NaikRanoji RaoShivarudraradhyaThippannaVenkataswamyNR Srinath

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The Raman Research Institute publishes theresearch activities carried out over the year innational and international peer-reviewedjournals. Each of the four research groups atRRI finds their work published in distinguishedjournals that focus on their specific researcharea. For the Theoretical Physics group theseinclude, but are not limited to, Physical Review,Classical and Quantum Gravity, Journal ofPhysics, Journal of Statistical Mechanics andBiophysics Journal. Research faculty andstudents from the Soft Condensed Matter grouphave their work published in journals likePhysical Review, Liquid Crystals, Journal ofPhysical Chemistry, Journal of ChemicalSciences, Journal of Applied Physics, EuropeanPhysical Journal, Journal of Nanoscience andNanotechnology and many more.

Publications of the Light and Matter Physicsgroup can be found in Physical Review, Journal

of Nanophotonics, Optical Express andCanadian Journal of Physics. The astronomersand astrophysicists use the Physical Review,Monthly Notices of the Royal AstronomicalSociety, Astrophysical Journal, Journal ofAstrophysics and Astronomy and others as ameans to share their work with the scientificcommunity around the world. 132 papersfeaturing RRI members as their authors and/orco-authors were published during the year.There were 17 publications in conferenceproceedings and 39 (30 in journals and 9 inconference proceedings) publications are inpress. Members at the institute expand anddiversify their work beyond the scope of highlyspecialised technical and science journals bypublishing books and/or articles for popularscience magazines.

A full list of the publications by each of theinstitute members is provided in Appendix I.

PUBLICATIONS

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ConferencesConferences and visits to various institutions athome and abroad play a significant role in theresearch activities of the institute members.Such events provide opportunities for theexchange of ideas and are often a starting pointfor future fruitful collaborations with otherresearchers from various institutions withinIndia and abroad. Last year, faculty andstudents of the institute attended numerousconferences in India, Australia, Japan, USA andEurope.

In addition, lectures and invited talks weregiven at a variety of workshops, internationalprogrammes, multinational project meetingsand training programmes. Members of theinstitute visited colleges around the country andspecially organised workshops on different

science and research topics to deliver lectures,talks and presentations.

A full list of the conferences visited by each ofthe institute members is provided in Appendix II.

Seminars and ColloquiaThursday colloquia are one of the numerousactivities promoted at the institute as a way toincrease the interactions between the variousresearch groups within RRI as well as thosebetween RRI members and invited speakersand their institutions. Apart from coveringrelevant science topics, the colloquia oftenintroduce new and interesting themes fromvarious other disciplines.

A C T I V I T I E Sother

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During the last year, RRI invited speakers fromall over the globe to deliver the Thursdaycolloquia. The topics covered a range of topics,including “Measuring Quantum Gravity”, “DataAssimilation – Interplay between Nonlinearityand Statistics”, “Neutrinos Breaking the LightBarrier?”, “Advanced Polymers for 3DTelepresence and Energy Conversion”, and“Water and a City”.

A complete list of the speakers, their lecturetopics and when they visited RRI is given inAppendix III.

Seminars at the institute are often delivered byvisiting faculty and researchers. Unlikecolloquia, seminars are intended to deepen theunderstanding and generate discussions on avery specific research theme. Usually, the topicscover the current progress of collaborativeprojects between RRI and the visitor’sinstitution, or themes of particular interest toRRI members.

A list of the visiting research faculty andresearchers to RRI during the last year is givenin Appendix IV.

In-house MeetingsThe RRI In-House Meeting is an annual eventthat aims to bring together the members of thedifferent research divisions, laboratories andsupport services of RRI to foster anappreciation amongst the community of thediversity of the scientific activities on campus.During the Meeting days, an assortment oftalks, poster presentations and informaldiscussions on a wide spectrum of topics isarranged. There are, sometimes, talks by invitedspeakers on topics of general interest andoutside the direct research themes of membersof the institute in addition to a social gathering.

Visiting ScholarsHigh priority is given to increasing the stream ofvisiting scholars to the institute. In today’s high-tech world of global connectivity the academicand research community is more open thanever before. Maintaining a nationally andinternationally open environment is crucial forthe success of every research institution.

Members at RRI recognise that and worktirelessly toward creating more opportunities fora larger number of scientists, researchers andengineers to visit the institute, contribute newideas and skills, while benefitting from theexpertise of RRI’s own members. Visits at RRIcan last from a few days to a few months andoften lead to important collaborative resultsand/or the conception of new, interestingprojects.

Last year, there were 117 scholars who visitedRRI from dozens of Indian and internationalinstitutions. RRI is happy to have so manyfriends and thanks all of them for making theenvironment in the institute so diverse, dynamicand vibrant.

A list of all visitors, where they come from andwhen they visited RRI can be found in AppendixIV.

Other activitiesPhD APhD APhD APhD APhD Awwwwwararararardeddeddeddedded

Satyam Kumar Gupta: Synthesis andcharacterisation of some non-conventionaldiscotic liquid crystals

Nagaraju DH: Electrochemical studies of someredox active bio-molecular and smallorganic molecules on nanomaterialsmodified surfaces

Bibhu Ranjan Sarangi: Organisation of sterols inmodel membranes

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Ruta Kale: A multi-wavelength study of radiohalos and relics in clusters of galaxies

Rakesh Kumar Pandey: Electron transfer andelectro catalytic studies on some organicand conducting polymer nanocomposite thinfilms

Anupam Kundu: Problems in transport theory

AV Radhakrishnan: Investigations on thepolymorphism of surfactant-DNA complexes

SubmittSubmittSubmittSubmittSubmittededededed

Peeyush Prasad: A network centric receiverarchitecture for low frequency arrays

Md. Arif Kamal: Influence of some membrane-active biomolecules on the phase behaviourof model lipid membranes

Antara Pal: Studies on the self-assembledstructures of ionic amphiphiles in water –influence of strongly binding counterionsand polymers

Tripta Bhatia: Experimental studies on statisticsand dynamics of some novel instabilities inlyotropic systems

GeneralThe following grants were received from theDepartment of Science and Technology duringthe year:

Journal ClubThe Journal Club at RRI, initiated in 1981, aimsat drawing the attention of members of theinstitute to exciting and interesting papers thatappear in scientific literature. Given the largenumber of papers published these days, it isnearly impossible for an individual to keep trackof developments outside their researchspecialities. The Journal Club tries to partlyremedy this situation by offering presentationsof a variety of recent papers of general interest.

The last Journal Club slot of the year istraditionally reserved to review the year’s NobelPrize Award in Physics. While speakers presenttheir selected papers, informal discussions,questions and demonstrations are stronglyencouraged as often they are the seeds ofbetter understanding that can lead to betterquality research.

A list of the papers reviewed during the JournalClub meetings last year is attached to theannual report as Appendix V.

Hindi CellUnder the guidance of the Official LanguageImplementation Committee of the institute,efforts were intensified to meet the targets fixedby the Annual Programme of the Ministry ofHome Affairs, Government of India. In thisdirection, all the concerned employees of theadministration were instructed to monitor theusage of the official language. Hindi workshops

were conducted to impart training oncomputers to work in Hindi at the institute.The “Official Language TrainingProgramme” was reoriented more towardsenhancing the working skills in the usageof Hindi. Most of the targets were achievedduring the year.

(Amount in lakhs)

PLAN Rs.3,898.00(Recurring & Non Recurring)

NON-PLAN Rs.142.00(Recurring)

TOTAL Rs.4,040.00

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ReservationsThe institute follows the reservation policy asfollowed by the Government of India scientificdepartments like the Department of Space andDepartment of Atomic Energy.

OthersThe RRI community is involved in various otheractivities ranging from organising specialconferences, meetings and workshops, andinviting college students to the campus, tohaving formal and informal dinners, sportstournaments, and a variety of culturalprogrammes both with invited performers andmembers of RRI themselves. Such activities areconsidered to be an integral part of themembers’ experience at the institute. Otherevents and activities such as in-housemeetings, concerts, formal faculty farewelldinners, college visits and more continue toenrich and diversify the academic life andatmosphere at the Raman Research Institute.

Public OutreachGlobal JeGlobal JeGlobal JeGlobal JeGlobal Jet Wt Wt Wt Wt Watchatchatchatchatch

RRI has become a partner in aninternational initiative that alsoincludes students from a localschool. Global Jet Watch (http://www.globaljetwatch.net/) is anew project that linksastronomers at Oxford Universitywith school children around theworld in order to carry outcutting edge research. Membersof RRI are involved in the settingup of a 20-inch opticaltelescope, the largest of its kindin Karnataka. One of the manyexciting things about the Indian

telescope is that its location allows it to observethe whole of the northern hemisphere as wellas a significant portion of the southernhemisphere, the only telescope in the projectnetwork to do so.

The aim of Global Jet Watch is to make theworld’s first continuous, round-the-clock,detailed monitoring programme for theprototypical micro-quasar SS433, also known asthe “Cosmic Corkscrew”. Observing the objectthroughout entire orbital periods, precessionperiods, and flaring events will allow a detailedunderstanding of the interplay betweenaccretion, jets and winds. SS433 persistentlyejects jets of plasma at a quarter of the speedof light, about an axis which precessesapproximately every six months to produce thecharacteristic corkscrew shape. A technique hasbeen developed to study individual “bullets” ofmatter as they emerge, but the exploitation ofthis incredible scientific resource is hindered bythe near-impossibility of obtaining sustainedmonitoring with sufficient time-resolution tofollow the rapid changes. It is immensely trickyto coax different observatories to coordinateobservations, and so Global Jet Watch wasdeveloped as a unique solution to this problem.

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Special small telescopes have been strategicallydeployed in schools in India, Chile, Australiaand South Africa with local professionalastronomers also being involved. Each night,the telescopes will obtain a spectrum of thehigh-speed jets which are emitted from SS433.

As part of the project, the telescope in India hasbeen set up at Jawahar Navodaya Vidyalaya(JNV) school in Dodaballapur, approximately anhour’s drive away from Bangalore. The school’sparticipation will make possible the monitoringof this unique object every few hours,something which would otherwise beimpossible given the time constraints imposedon the use of professional telescopes. Dataobtained by the school observatory will beprocessed by computers in Oxford, and a webinterface will be developed to provide theschools with results so that the school childrencan monitor the progress of the rapidly evolvingjets themselves, and understand how theirobservations tie up with those obtained by theother schools around the world. Rather thansimply learning about scientific discoveries, theparticipating pupils will be making thediscoveries themselves.

The IntThe IntThe IntThe IntThe International Science Schoolernational Science Schoolernational Science Schoolernational Science Schoolernational Science School

The Professor Harry Messel InternationalScience School (ISS) has been conducted by theScience Foundation for Physics, University ofSydney, Australia, since 1962. It brings togetherabout 140 students from around the world fortwo weeks of advanced study on topics ofmodern science. The foundation sets aside fivescholarships at the ISS for Indian high schoolstudents. This programme is conducted onceevery two years. All ISS scholars are chosen ontheir academic ability and, depending on theircountry, must compete for an ISS scholarshipthrough a written essay, an interview or anexam.

RRI has been coordinating this event from Indiasince 2007 and has been identifying studentswishing to participate in the ISS. RRI has anintensive selection process to choose the fivestudents for the ISS, which includes a writtentest with general questions and an essay as wellas an interview. The selected students areawarded a scholarship and are also given travelcharges to the University of Sydney and back toIndia. RRI has been taking the help of theKishore Vaigyanik Protsahan Yojana (KVPY) ofthe Indian Institute of Science to shortlistprospective candidates (usually in classes XIand XII) for the ISS from across the country.

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Papers in Journals

1 Atom interferometry and the gravitationalredshiftSinha, Supurna; Samuel, JosephClassical and Quantum Gravity 2828282828, 145018,2011

2 Non-local geometric phase in two-photoninterferometryMartin A; Alibart O; Flesch JC; Samuel,Joseph; Sinha, Supurna; Tanzilli S; Kastberg AEurophysics Letters 9999977777, 10003, 2012

3 Focus section on quantum gravity - 25 yearsof quantum gravitySamuel, JosephClassical and Quantum Gravity 2828282828, 150301,2011

4 Tops and writhing DNASamuel, Joseph; Sinha, SupurnaJournal of Statistical Physics 111114343434343, 399, 2011

5 Gravitational radiation for extreme mass ratioinspirals to the 14th post-Newtonian orderFujita, RyuichiProgress of Theoretical Physics 121212121277777, 583,2012

6 The Japanese space gravitational waveantenna-DECIGOKawamura, Seiji*; Ando M*; Seto N*; SatoS*; Nakamura T*; Fujita, Ryuichi and 132 co-authorsClassical and Quantum Gravity 2828282828, 094011,2011

7 The 2.5PN linear momentum flux andassociated recoil from inspiralling compactbinaries in quasi-circular orbits: nonspinningcaseMishra CK; Arun KG; Iyer BRPhys. Rev. D 8585858585, 044021, 2012

8 Gravitational waveforms for binary black holesIyer BRInternational Journal of Modern Physics D 1111100000,2081, 2011

9 Classical orbital magnetic moment in adissipative stochastic systemKumar NPhysical Review E 8585858585, 011114, 2012

APPENDIX 1Publications

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10 Light scattering from a magnetically tunabledense random medium with dissipation:ferrouidShalini M*; Sharma D*; Deshpande AA;Mathur D*; Ramachandran, Hema; Kumar NEurophysics Journal D 6666666666, 30, 2012

11 Comment on Classical Langevin dynamics ofa charged particle moving on a sphere anddiamagnetism: A surpriseKumar N; Kumar K Vijay; Deshpande AAEurophysics Letters 9999977777, 17003, 2012

12 Effect of injected noise onelectromagnetically induced transparency andslow lightRanjith V; Kumar NCurrent Science 111110000011111, 653, 2011

13 Stochastic pump of interacting particlesChaudhuri, Debasish*; Dhar, AbhishekEurophysics Letters 9999944444, 30006, 2011

14 Generating function formula of heat transferin harmonic networksSaito, Keiji*; Dhar, AbhishekPhysical Review E 8383838383, 041121, 2011

15 Tunable thermal conductivity in defectengineered nanowires at low temperaturesDhara, Sajal*; Solanki, Hari S*; Pawan RArvind*; Singh, Vibhor*; Sengupta,Shamashis*; Chalke BA*; Dhar, Abhishek and3 co-authorsPhysical Review B 8888844444, 121307, 2011

16 Nonequilibrium density-matrix description ofsteady-state quantum transportDhar, Abhishek; Saito, Keiji*; Hanggi, Peter*Physical Review E 8585858585, 011126, 2012

17 Work fluctuations for a harmonic oscillatordriven by an external random forceSabhapandit, SanjibEurophysics Letters 9696969696, 20005, 2011

18 Heat and work fluctuations for a harmonicoscillatorSabhapandit, SanjibPhysical Review E 8585858585, 021108, 2012

19 Record statistics of continuous time randomwalkSabhapandit, SanjibEurophysics Letters 9999944444, 20003, 2011

20 Additivity Principle in High-DimensionalDeterministic SystemsSaito K; Dhar, AbhishekPhys. Rev. Lett. 111110000077777, 250601, 2011

21 Dynamics of a flexible polymer in planarmixed flowDas, Dipjyoti; Sabhapandit, Sanjib; Das,DibyenduJ. Phys.: Conf. Ser. 292929292977777, 012007, 2011

22 Causal topology in future and pastdistinguishing spacetimesParrikar, Onkar*; Surya, SumatiClassical and Quantum Gravity 2828282828, 155020,2011

23 The diffeomorphism constraint operator inloop quantum gravityLaddha, Alok; Varadarajan, MadhavanClassical and Quantum Gravity 2828282828, 195010,2011

24 Early-time particle dynamics and non-affinedeformations during microstructure selectionin solidsSengupta, Surajit*; Rao, Madan;Bhattacharya, Jayee*Journal of Physics: Condensed Matter 2323232323,295402, 2011

25 Multispecies model with interconversion,chipping, and injectionSachdeva, Himani*; Barma, Mustansir*; Rao,MadanPhysical Review E 8888844444, 031106, 2011

26 Bidirectional transport in a multispeciestotally asymmetric exclusion-process modelMuhuri, Sudipto; Shagolsem, Lenin*; Rao,MadanPhysical Review E 888884,4,4,4,4, 031921, 2011

27 Topological parameters in gravityKaul, Romesh K; Sengupta, SandipanPhys. Rev. D. 8585858585, 024026, 2012

28 Spatiotemporal regulation of chemicalreactions by active cytoskeletal remodelingChaudhuri, Abhishek; Bhattacharya B*;Gowrishankar, Kripa; Mayor, Satyajit*; Rao,MadanProceedings of the National Academy ofSciences of the United States of America111110808080808, 14825, 2011

29 Integrin adhesion drives the emergentpolarization of active cytoskeletal stresses topattern cell delaminationMeghana C*; Ramdas, Nisha*; Hameed FM*;Rao, Madan; Shivashankar GV*; NarasimhaM*Proceedings of the National Academy ofSciences 111110808080808, 9107, 2011

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30 ATLBS extended source sample: the evolutionin radio source morphology with flux densitySaripalli L; Subrahmanyan R; Thorat K;Ekers RD; Hunstead RW; Johnston HM;Sadler EMAstrophysical Journal Supplement 111119999999999, 27,2012

31 PeV gamma rays from interactions of ultrahigh energy cosmic rays in the milky wayGupta, NayantaraAstroparticle Physics 3535353535, 503, 2012

32 Discovery of a giant radio halo in a massivemerging cluster at z = 0.443Dwarakanath KS; Malu SS; Kale, RutaJournal of Astrophysics and Astronomy 3232323232,529, 2011

33 Multi-frequency studies of radio relics in thegalaxy clusters A4038, A1664 and A786Kale, Ruta; Dwarakanath KSThe Astrophysical Journal 777774444444444, 46, 2012

34 HI in Arp 72 and similarities with M51-typesystemsSengupta, Chandreyee; Saikia DJ;Dwarakanath KSMonthly Notices of the Royal AstronomicalSociety 420420420420420, 2, 2012

35 Dust-driven wind from disk galaxiesSharma, Mahavir; Nath BB; Shchekinov, Yuri*Astrophysical Journal Letters 736736736736736, L27, 2011

36 Intracluster gas pressure, entropy injectionand redshift evolutionNath BB; Majumdar, S*Monthly Notices of the Royal AstronomicalSociety 444441111166666, 279, 2011

37 The Australia Telescope Compact ArrayBroadband Backend (CABB)Wilson, Warwick E; Ferris RH; Axtens P; BrownA; Davis E; Hampson G; Leach, M; Roberts P;Saunders S; Koribalski BS; Caswell JL; Lenc E;Stevens J; Voronkov, MA; Wieringa MH; BrooksK; Edwards PG; Ekers RD; Emonts B; HindsonL; Johnston S; Maddison ST; Mahony EK; MaluSS; Massardi, M; Mao MY; McConnell D;Norris RP; Schnitzeler D; Subrahmanyan R;Urquhart JS; Thompson MA; Wark RMMonthly Notices of the Royal AstronomicalSociety 444441111166666, 832, 2011

38 The Australia telescope 20 GHz survey:hardware, observing strategy, and scanningsurvey catalogHancock, Paul Jacob*; Roberts, Paul*;Kesteven, Michael J*; Ekers, Ronald D*;Subrahmanyan R; 15 Co-authorsExperimental Astronomy 3232323232, 147, 2011

39 Imaging the epoch of reionization: limitationsfrom foreground confusion and imagingalgorithmsVedantham, Harish; Udaya Shankar N;Subrahmanyan RThe Astrophysical Journal 777774545454545, 176, 2012

40 18 GHz SZ measurements of the bulletclusterMalu SS; Subrahmanyan RJournal of Astrophysics and Astronomy 3232323232,541, 2011

41 Design and optimization of a cylindrical X-raydetector using finite element methodDuraichelvan R; Srinivas AR; Ateequlla; Paul,Biswajit; Rishin PV; Cowsik RJournal of Mechanical Engg Vol. 99999, p55-64,2011

42 Studies of quasi-periodic oscillations in theblack hole transient XTE J1817-330Roy, Jayashree*; Agrawal PC*; Paul, Biswajit;Duorah, K*Monthly Notices of the Royal AstronomicalSociety 444441212121212, 1011, 2011

43 Eclipse Timings of the LMXB XTE J1710-281:Orbital period glitchesJain, Chetana; Paul, BiswajitMonthly Notices of the Royal AstronomicalSociety 444441111133333, 2, 2011

44 Suzaku observation of the transient X-raypulsar GRO J1008-57Naik, Sachindra*; Paul,Biswajit; Kachhara, Chetan*; Vadawale,Santosh V*Monthly Notices of the Royal AstronomicalSociety 444441111133333, 241, 2011

45 RXTE-PCA observations of 1A 1118-61: timingand spectral studies during an outburstDevasia, Jincy*; James, Marykutty; Paul,Biswajit; Indulekha Kavila*Monthly Notices of the Royal AstronomicalSociety 44444111114,4,4,4,4, 1023, 2011

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46 Prospect of polarization measurements fromblack hole binaries in their thermal state witha scattering polarimeterMaitra, Chandreyee; Paul, BiswajitMonthly Notices of the Royal AstronomicalSociety 444441111144444, 2618, 2011

47 Pulse profile stability of the Crab pulsarJain, Chetana*; Paul, BiswajitResearch in Astronomy and Astrophysics 1111111111,1134, 2011

48 Search for pulsations in the LMXB EXO 0748-676Jain, Chetana; Paul, BiswajitResearch in Astronomy and Astrophysics 1111111111,,,,,577, 2011

49 Interference detection in Gaussian noiseBaddi, Raju RAstronomical Journal 111114444411111, 190, 2011

50 Helium line detections from extended low-density warm-ionized medium at 1.4 ghzBaddi, Raju RAstronomical Journal 111114242424242, 154, 2011

51 A survey of radio recombination lines usingthe Ooty radio telescope at 328 mhz in theinner galaxyBaddi, Raju RAstronomical Journal 111114343434343, 26, 2012

52 RRL Observations with ORT at 328 MHz andWSRT at 1.4 GHz from EldwimBaddi, Raju RAstronomical Journal 111114343434343, 45, 2012

53 QUBIC: The QU bolometric interferometer forcosmologyBattistelli E*; Bau A*; Malu SS and 61 co-authorsAstroparticle Physics 3434343434, 705, 2011

54 X-ray spectroscopy of the high-mass x-raybinary pulsar centaurus x-3 over its binaryorbitNaik, Sachindra*; Paul, Biswajit; Ali, Zulfikar*Astrophysical Journal, 737373737377777, 79, 2011

55 Transient high mass x-ray binariesPaul, Biswajit; Naik, SachindraBulletin of the Astronomical Society of India3939393939, 429, 2011

56 Timing and spectral studies of the transient x-ray pulsar GX 304-1 during an outburstDevasia, Jincy; James, Marykutty; Paul,Biswajit; Indulekha, Kavila

Monthly Notices of the Royal AstronomicalSociety 444441111177777, 348, 2011

57 Solar cycle phase dependence ofsupergranular fractal dimensionPaniveni U*; Krishan, Vinod*; Singh J*;Srikanth RJournal of Astrophysics and Astronomy 3232323232,265, 2011

58 A high speed networked signal processingplatform for multi-element radio telescopesPrasad, Peeyush; Subrahmanya CRExperimental Astronomy 3333311111, 1, 2011

59 Radio-Optical imaging of ATLBS surveyThorat, KshitijJournal of Astrophysics and Astronomy 3232323232,495, 2011

60 Double relics in the outskirts of A3376:accretion ows meet merger shock?Kale, Ruta; Dwarakanath KS; Bagchi,Joydeep*; Paul, Surjit*Journal of Astrophysics and Astronomy 3232323232,533, 2011

61 A zoo of radio relics: cluster cores tofilamentsKale, Ruta; Dwarakanath KSJournal of Astrophysics and Astronomy 3232323232,537, 2011

62 Carbon recombination lines towards theRiegel-Crutcher cloud and other cold H Iregions in the inner galaxyRoshi, D Anish; Kantharia NG*Monthly Notices of the Royal AstronomicalSociety 444441111144444, 519, 2011

63 Detecting neutral hydrogen in emission atredshift z ‘ 1Kandai, Nishikanta*; Sethi, Shiv K; MatteoTD*; Croft, Rupert AC*; Springel, Volker*;Jana, Anirban*; Gardner, Jeffrey P*Monthly Notices of the Royal AstronomicalSociety 444441111155555, 2580, 2011

64 Theoretical estimates of two-point shearcorrelation functions using tangledmagneticfieldsPandey, Kanhaiya; Sethi SKAstrophysical Journal 7777748,48,48,48,48, 27, 2012

65 The nonmodular topological phase and phasesingularitiesBhandari, RajendraPhysical Letters A 3333375,75,75,75,75, 3562, 2011

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66 Ehrenfest’s Theorem and Nonclassical Statesof Light. 1. Ehrenfest’s theorem in quantummechanics.George, Lijo T; Sudheesh C*; Lakshmibala S*;Balakrishnan V*Resonance 111117(1),7(1),7(1),7(1),7(1), 23, 2012

67 Ehrenfest’s theorem and nonclassical statesof light: 2 Dynamics of nonclassical states oflightGeorge, Lijo T; Sudheesh C*; Lakshmibala S*;Balakrishnan V*Resonance 111117(2),7(2),7(2),7(2),7(2), 192, 2012

68 Non-Gaussianity and direction-dependentsystematics in HST key project dataShashikant; Saini TDMonthly Notices of the Royal AstronomicalSociety, 444441111155555, 2594, 2011

69 Transport coefficients for the shear dynamoproblem at small Reynolds numbersSingh, Nishant K; Sridhar SPhysical Review E 8383838383, 056309, 2011

70 Magnetohydrodynamics turbulence: Anastronomical perspectiveSridhar SPramana 777777,7,7,7,7, 185, 2011

71 Timing and broad-band spectroscopy of 1A1118-61 with SuzakuMaitra C; Paul, Biswajit; Naik, SachindraMonthly Notices of the Royal AstronomySociety 420420420420420, 2307, 2012

72 Active galactic nuclei feedback and clustersNath BBJournal of Astronomy & Astrophysics, 3232323232,545, 2012

73 Non equilibrium carbon ionization states andthe extragalactic far UV background with HeIIabsorptionVasiliev EO*; Sethi SK; Nath BBAstrophysics & Space Sciences, 335335335335335, 211,2011

74 Radiation and thermal pressure drivengalactic windsNath BBAstronomical and Astrophysical Transaction,2222277777, 183, 2012

75 Dust in the IGM: pro and contraShchekinov, Y*; Nath BBAstrophysics & Space Sciences, 335335335335335, 207,2011

76 4-(Benzyloxy) phenyl 4-hexadecyloxy-3-methoxybenzoateAl-Eryani WFA; Srinivasa HT; Jeyaseelan S;Sadashivaiah T; Devarajegowda HCActa. Crystallographica E 6767676767, 840, 2011

77 Anticlinic smectic C phase in new and novelfive-ring hockey stick-shaped compoundsRadhika S; Srinivasa HT; Sadashiva BKLiquid Crystals 3838383838,785, 2011

78 Rheological properties of a chiral liquidcrystal exhibiting type-II characterRajeswari M*; Ananthaiah J*; Dabrowski R*;Sastry VSS*; Dhara S*; Sadashiva BKMolecular Crystals and Liquid Crystals 545454545477777,39, 2011

79 Calorimetric study of the effect of bent-shaped dopant molecules on the criticalbehavior at the nematic-smectic-Ad phasetransitionSasaki Y*; Ema K*; Le KV*; Takezoe H*;Dhara S*; Sadashiva BKPhysical Review E 8383838383, 061701, 2011

80 Magnetic susceptibility studies on a ternarylyotropic liquid crystal systemVijayaraghavan DMolecular Crystals and Liquid Crystals 545454545477777,181, 2011

81 Magnetic susceptibility and electricalconductivity studies on the aqueous solutionsof two nonionic surfactantsVijayaraghavan DJournal of Molecular Liquids 111116666666666, 76-80,2012

82 Observation of hysteresis in the properties ofa ternary lyotropic liquid crystal systemVijayaraghavan DMolecular Crystals and Liquid Crystals 545454545477777,189, 2011

83 Experimental studies of the jammingbehaviour of triblock copolymer solutions andtriblock copolymer-anionic surfactantmixturesBasak, Rajib; Mukhopadhyay, Nabaneeta;Bandyopadhyay, RanjiniEuropean Physical Journal E 3434343434, 103, 2011

84 Bit slice addressing of fast switching bi-stabledisplays and multi-bit slice addressing ofactive matrix liquid crystal displaysRuckmongathan TNJournal of Display Technology 88888, 198, 2012

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85 Cross pairing of select and data voltages todisplay grayscales in liquid crystal displaysRuckmongathan TNJournal of Display Technology 77777, 633, 2011

86 Method to display gray shades in rmsresponding matrix displayRuckmongathan TNPatent No. US8081179B2 date Dec. 20,2011

87 A simple and low-cost ultramicroelectrodesfabrication and characterization method forundergraduate studentsSur, Ujjal Kumar+; Dhason A;Lakshminarayanan VJournal of Chemical Education 8989898989, 168, 2012

88 Structure-property correlation of a hockeystick-shaped compound exhibiting N-SmA-SmCa phase transitionsSathyanarayana P*; Radhika S; SadashivaBK; Dhara, Surajit*Soft Matter 88888, 2322, 2012

89 H-shaped azoester-oxymethylene containingtwin liquid crystalline compoundsVaria MC; Kumar, Sandeep; Prajapati AKLiquid Crystals, 3939393939, 365, 2012

90 Electron transfer studies of redox probes inbovine milkShrikrishnan S; Lakshminarayanan VJournal of Colloid and Interface Science 333337070707070,124, 2012

91 A simple electro-optic technique for studyingthe electroclinic effect in the smectic A*phaseDatta, Soma; Roy, ArunLiquid Crystals 3838383838, 1193, 2011

92 Anthraquinone-based discotic liquid crystals:new monomers and dimersPrasad, Veena*; Roy, Arun; Nagaveni NG*;Gayathri K*Liquid Crystals 3838383838, 1301, 2011

93 Electro-optical investigations and effect ofasymmetry in bent-core liquid crystalsBalamurugan S*; Kannan P*; Yadupati K;Roy, ArunLiquid Crystals 3838383838, 1199, 2011

94 Randomly polarised smectic A phaseexhibited by bent-core molecules:experimental and theoretical studiesGupta, Meenal; Datta, Soma; Radhika S;Sadashiva BK; Roy, ArunSoft Matter 77777, 4735, 2011

95 CdSe quantum dots in a columnar matrixKumar, Sandeep; Sagar, Laxmi Kishore*Chemical Communications 4444477777, 12182, 2011

96 Novel triphenylenoimidazole discotic liquidcrystalsKumar, Sandeep; Gupta, Satyam KumarTetrahedron Letters 5252525252, 5363, 2011

97 Discovery of a novel ferrielectric phase of five-layer periodicity in binary mixtures of chiralsmectic liquid crystals exhibiting unusualreversed phase sequenceChandani ADL*; Fukuda, Atsuo*; Kumar,Sandeep; Vij, Jagdish K*Liquid Crystals 3838383838, 663, 2011

98 Electro-optical switching studies on 1,3-phenylene based banana shaped liquidcrystalsBalamurugan S; Kannan P; Yadupati Y; Roy,ArunJ. Mol. Struct, 11111000000000011111, 118, 2011

99 Theory of the asymmetric ripple phase inachiral lipid membranesKamal, Md. Arif; Pal, Antara; Raghunathan VA;Rao, MadanEurophysics Letters 9595959595, 48004, 2011

100 Collapse and coacervation of a lamellarphase by inter-headgroup bridgingPal, Antara; Bharath P*; Dastidar SG*;Raghunathan VASoft Matter 88888, 927, 2012

101 Temperature driven annealing of perforationsin bicellar model membranesNieh, Mu-Ping*; Raghunathan VA; Pabst,Georg*; Harroun, Thad*; Nagashima,Kazuomi*; Morales, Hannah*; Katsaras,John*; Macdonald, Peter*Langmuir 2222277777, 4838, 2011

102 Effect of an electric field on defects in anematic liquid crystal with variable surfaceancheringKumar, Arun T*; Sastry VSS*; Ishikawa, Ken*;Takezoe, Hideo*; Madhusudana NV; Dhara,Surajit*Liquid Crystals 38,38,38,38,38, 971, 2011

103 Carbon based liquid crystals: art and scienceBisoyi, Hari Krishna; Kumar, SandeepLiquid Crystals, 38, 38, 38, 38, 38, 1427-49, 2011

104 Phase-sensitive microwave optical doubleresonance in an N systemPreethi TM; Manukumar M; Asha K; Vijay J*;Roshi, D Anish; Narayanan, AndalEurophysics Letters 9595959595, 34005, 2011

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105 Combined ion and atom trap for low-temperature ion-atom physicsRavi K; Lee S; Sharma A; Werth G*; RangwalaSAApplied Physics B 111110000077777, 971, 2012

106 Nonlinear optical characterization of newthiophene-based conjugated polymers forphotonic switching applicationsHegde, Pramod Kumar*; Adhikari AV*;Manjunatha MG*; Sandeep, Suchand, CS;Philip, RejiAdvances in Polymer Technology 3030303030, 312,2011

107 Intramolecular charge transfer and Z-scanstudies of a semiorganic nonlinear opticalmaterial sodium acid phthalate hemihydrate:a vibrational spectroscopic studySajan D*; Vijayan N*; Safakath K; Philip, Reji;Joe, I Hurbert*Journal of Physical Chemistry A 111111111155555, 8216,2011

108 Synthesis and nonlinear opticalcharacterization of new 1,3,4-oxadiazolesChandrakantha, B*; Isloor, Arun M*; Philip,Reji; Mohesh, M*; Shetty, Prakash*; Vijesh,AM*Bulletin of Materials Science 3434343434, 887, 2012

109 Synthesis, growth and characterization ofnovel second harmonic nonlinear chalconecrystalD’silva ED*; Rao, Narayan D*; Philip, Reji;Butcher, Ray J*; Rajnikant*; DharmaprakashSM*Journal of Physics and Chemistry of Solids7272727272, 824, 2011

110 Nonlinear absorption and photoluminescenceemission in nanocomposite films of Fuchsinebasic dye-polymer systemSreekumar G*; Frobel, PG Louie*; Sreeja S*;Suresh SR*; Mayadevi S*; Muneera CI*;Sandeep, Suchand CS; Philip, Reji;Mukharjee, Chandrachur*Chemical Physics Letters 506506506506506, 61, 2011

111 Synthesis and nonlinear optical properties ofLead Telluride nanorodsSridharan, Kishore*; Tamilselvan V*; YuvarajD*; Rao, Narasimha K*; Philip, RejiOptical Materials 3434343434, 639, 2012

112 Improved optical limiting in dispersible carbonnanotubes and their metal oxide hybridsAnand, Benoy*; Susana, Addo Ntim*;Muthukumar, V Sai*; Sai, S Siva Sankara*;Philip, Reji; Mitra, Somenath*Carbon 4949494949, 4767, 2011

113 An open aperture z-scan study ofSr2CeO4bluephosphorSeema R; Sandeep; Suchand CS; Philip, Reji;Kalarikkal NJournal of Alloys and Compounds 509509509509509, 8573,2011

114 Second harmonic chalcone crystal: synthesis,growth and characterizationD’silva ED*; Rao, Narayan D*; Philip, Reji;Butcher, Ray J*; Rajnikant*; DharmaprakashSM*Physica B 406406406406406, 2206, 2011

115 Design and synthesis of a new thiophenebased donor-acceptor type conjugatedpolymer with large third order non-linearoptical activityMurthy, Vishnu; Philip, Reji, et al.Synthetic Metals, 111116666611111, 1699, 2011

116 Nonlinear and magneto-optical transmissionstudies on magnetic nanouids of non-interacting metallic nickel nanoparticlesMary APR*; Sandeep, Suchand CS;Narayanan TN*; Philip, Reji; Moloney,Padraig*; Ajayan PM*; Anantharaman MR*Nanotechnology 2222222222, 375702, 2011

117 Synthesis, electrochemical and opticalstudies of new cyanopyridine basedconjugated polymers as potential fluorescentmaterialsVishnumurthy KA*; Sunitha MS*; Safakath K;Philip, Reji; Adhikari AV*Polymer 5252525252, 4174, 2011

118 New diphenylamine-based donor-acceptor-type conjugated polymers as potentialphotonic materialsVishnumurthy, KA*; Sunitha, MS*; Philip,Reji; Adhikari, Airody Vasudeva*Reactive and Functional Polymers 7777711111, 1119,2011

119 Nonlinear optical properties of nanosizedrare-earth-doped strontium barium niobateceramicsNuja, J*; Sandeep, Sandeep CS; Philip, Reji;Nandakumar, K*Spectroscopy Letters 4444444444, 334, 2011

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120 Near-resonant two-photon absorption inluminescent CdTe quantum dotsKhatei, Jayakrishna*; Sandeep, Suchand CS;Philip, Reji; Rao, Koteswara KSR*Applied Physics Letters 111110000000000, 081901, 2012

121 Two-photon assisted excited state absorptionin multiferroic YCrO3 nanoparticlesKrishnan, Shiji*; Sandeep, Suchand CS;Philip, Reji; Kalarikkal, Nandakumar*Chemical Physics Letters 529529529529529, 59, 2012

122 Effects of disorder on the optical properties ofCVD grown polycrystalline graphenePodila, Ramakrishna*; Anand, Benoy*; Spear,John T*; Puneet P*; Philip, Reji; Siva, SankaraSai S*; Rao, Apparao M*Nanoscale 44444, 1770, 2012

123 Photoinduced transparency of effective threephoton absorption coefficient forfemtosecond laser pulses in Ge16As29Se55thin filmsBarik AR; Adarsh KV; Sandeep, Suchand;Philip, Reji; ZhaoD; Jain HApplied Physics Letters, 9898989898, 201111, 2011

124 Dynamics of photothermally createdvaporous, gaseous, and mixed microbubblesDharmadhikari AK* ; Dharmadhikari JA*;Mahulkar, Amit V*; Ramanandan, Gopika*;Ramachandran, Hema; Pandit, Aniruddha B*;Mathur, Deepak*Journal of Physical Chemistry C 111111111155555, 6611,2011

125 Quantum walk of light in frequency space andits controlled dephasingPandey, Deepak; Satapathy, Nandan; MeenaMS; Ramachandran, HemaPhysical Review A 8888844444, 042322, 2011

126 Operator-sum representation for bosonicGaussian channelsIvan, J SolomonPhysical Review A 8888844444, 04311, 2011

127 Robustness of non-gaussian entanglementagainst noisy amplifier and attenuatorenvironmentsSabapathy, Krishna Kumar*; Ivan, J Solomon;Simon RPhysical Review Letters 11111000007,7,7,7,7, 130501, 2011

128 Electromagnetically induced transparencywith quantum interferometryBhattacharjee, Anindita*; Dastidar, KrishnaRaiJournal of Chemical Physics 111113636363636, 084301,2012

129 Classical light analogue of the non-localAharonov-Bohm effectSatpathy,Nandan; Pandey, Deepak; Mehta,Poonam; Sinha, Supurna; Samuel, Joseph;Ramachandran, HemaEurophysics Letters 9999977777, 50011, 2012

130 Plasmonic, low frequency Raman and non-linear optical studies on copper-silicananocompositesSatyabrata, Mohapatra*; Mishra YK*; WarrierAM; Philip, Reji; Sahoo S* Arora AK; AvasthiDK Plasmonics 77777, 25, 2012

131 Electrochemical and nonlinear optical studiesof new d-a type -conjugated Polymers carrying3,4-Benzyloxythiophene, Oxadiazole, and3,lkoxythiophene systemsSunitha MS*; Adhikari, Airody Vasudeva*;Vishnumurthy KA*; Smijesh N; Philip, RejiChemistry Letters 4444411111, 234, 2012

132 Online reference zone: A gateway to referenceresources in science and technologyMeera BM; Ummer, RehanaSRELS Journal of Information Management4949494949, 55, 2012

Book Chapter1. Thomson X-ray Polarimeter for a Small

SatelliteRishin PV; Paul, Biswajit; et al. 20124th International MAXI Workshop, The firstyear of MAXI, Monitoring Variable X-raySources, Editors, Mihara T, Serino M., Tokyo,p371

2. Orbital evolution of X-ray binaries and quasi-periodic oscillations in X-ray pulsarsPaul, Biswajit; Raichur H; Jain C; James M;Devasia J; Naik SBulletin of the Astronomical Society of India;Conference Series, Vol 3, p29, Proceedings ofthe 29th meeting of the Astronomical Societyof India

Journals Special Issue EditionProceedings of the International Conferenceon Diffuse Relativistic PlasmasRaman Research Institute March 1-4, 2011Edited by Dwarakanath KS; Rudnick,Lawrence; Udaya Shankar N; Venturi, TizianaJournal of Astrophysics and Astronomy, 32, 32, 32, 32, 32,425, 2011

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Popular Articles1. Sunyaev-Zeldovich effect : Shadows in the

cosmic radiationNath BBResonance 111116(5)6(5)6(5)6(5)6(5), 428, 2011

2. Book Review for Annual Review of Astronomy& AstrophysicsNath BBCurrent Science 111110000011111, 11, 2011

3. Reminiscing RadUdaya Shankar NJournal of Astrophysics and Astronomy 32(4)32(4)32(4)32(4)32(4),615, 2011

In Conference Proceedings1 Gravitational waves from binary black holes

Iyer BRProceedings of the Chandrasekhar CentenaryConference (CHANDRA 2010)Ed. Padmanabhan T Pramana, 7777777777, 119,2011

2 In search of a covariant quantum measureSurya, SumatiJ. Phys. Conf. Ser. 306306306306306, 012018, 2011

3 Phononic heat conduction in disorderedcrystalsDhar, AbhishekAIP Conference Proceedings Vol. 1349. P-6.Solid State Physics Proceedings of the 55th

DAE Solid State Physics Symposium, 26-30December 2010, Manipal, India, 2011

4 Gray scales by cross pairing of select anddata voltages in liquid crystal displaysRuckmongathan TNSID ‘11 Digest, Proceedings of Symposium ofSociety for Information Display pp1326-1329,2011

5 Time-resolved spectroscopy of femtosecondlaser-induced carbon plasma in the rough,medium and high vacuum regimesAnoop KK; Remya R Mohan; Rose, Priya T;Philip, RejiProceedings of National Laser Symposium-20, January 2012

6 The open aperture z-scan studies on biferroicYCrO3Krishnan, Shiji*; Sandeep, Suchand CS; Reji,Philip; Kalarikkal, Nandakumar*

AIP Conference Proceedings Vol.1349 onSolid State Physics, 2011Proceedings of the 55th DAE solid statephysics symposium, held at Manipal, (India)from 26-30 December 2010, p 1277, 2011

7 Luminescence and optical limiting propertiesof sr2ceo4 blue emitterSeema R*; Sandeep, Suchand CS; Philip,Reji; Nandakumar, Kalarikkal*AIP Conference Proceedings Vol.1349 onSolid State Physics, 2011Proceedings of the 55th DAE solid statephysics symposium,held at Manipal, (India)from 26-30 December 2010, p 1273, 2011

8 Tunable optical limiting action due to non-linear absorption in ZnO/Ag nanocompositesRashu S*; Vijayan C*; Sandeep, Suchand CS;Philip, RejiAIP Conference Proceedings Vol.1349 onSolid State Physics, 2011Proceedings of the 55th DAE solid statephysics symposium, held at Manipal, (India)from 26-30 December 2010, p 425, 2011

9 Synthesis and third-order nonlinear opticalstudies of four-coordinated Copper(i)complexesSampath, Kumar HC*; Rudresha BJ*; Bhat,Ramachandra B*; Philip, Reji; Row, Guru TN*AIP Conference Proceedings Vol.1391 onoptics: phenomena, materials, devices, andcharacterization: Optics 2011: InternationalConference on Light Solid State Physics,P-671, 2011

10 Nonlinear optical properties of a newlysynthesized Thiophene based conjugatedpolymerSunitha MS*; Adhikari, Airody Vasudeva*;Vishnumurthy KA*; Philip, RejiiAIP Conference Proceedings Vol.1391 onoptics: phenomena, materials, devices, andcharacterization: Optics 2011: InternationalConference on Light Solid State Physics,P-703, 2011

11 Nonlinear optical studies of the sol-gelderived lithium Tetraborate thin filmDhanuskodi S*; Mohandoss R*; Philip, RejiAIP Conference Proceedings Vol.1391 onoptics: phenomena, materials, devices, andcharacterization: Optics 2011: InternationalConference on Light Solid State Physics,P- 686, 2011

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12 Indigo carmine dye-polymer nanocompositefilms for optical limiting applicationsSreeja S*; Mayadevi S*; Suresh SR*; FrobelPG Louie*; Philip, RejiAIP Conference Proceedings Vol.1391 onoptics: phenomena, materials, devices, andcharacterization: Optics 2011: InternationalConference on Light Solid State Physics,P-618, 2011

13 Optical nonlinearity and power limiting inorganic molecules and nanocompositesPhilip, Reji; Thomas, Jayan*Proceedings of the SPIE Vol. 8113, p81130J-1, Linear and Nonlinear Optics of OrganicMaterials XI, Ed by Jean-Michel Nunzi, RachelJakubiak, Theodore G Goodson III, ManfredEich, 2011

14 Synthesis and Characterization of a NewConjugated Polymer Bearing Pyrazole andThiophene Moieties as Potent NLO MaterialVishnumurthy KA*; Adhikari, AirodyVasudeva*; Sunitha MS*; Philip, RejiAIP Conference Proceedings Vol.1391 onoptics: phenomena, materials, devices, andcharacterization: Optics 2011: InternationalConference on Light Solid State PhysicsP-652, 2011

15 RRI-GBT Multi-Band Receiver and Pulsar-Emission-Cone TomographyDeshpande AA (on behalf of the RRI-GBTMulti-Band Receiver Team)2011, Proceedings of URSI-GA 2011, sessionJ11-7

16 A model of the warped discs in the GalacticcentreSaini TD; Sridhar SProceedings of the 29th Meeting of theAstronomical Society of India, held 23-25February, 2011 ASI Conference Series, Vol. 3,35 (2011), edited by Khare P and Ishwara-Chandra CH

17 Implementation of Library 2.0 technology toinformation literacyNagaraj MN; Naveen Mathad CNational Conference on Information Literacyon Competencies of Higher Learning andResearch, Tumkur University, 21 – 22 October2011, page 247

IN PRESSIn JournalsIn JournalsIn JournalsIn JournalsIn Journals

1 A ‘Gaussian’ for diffusion on the sphereGhosh, Abhijit; Samuel, Joseph; Sinha,SupurnaEurophysics Letters 9898989898, 30003, 2012

2 Biopolymer elasticity: Mechanics and thermalfluctuationsSinha, Supurna; Samuel, JosephPhys. Rev. E 8585858585, 041802, 2012

3 Nonequilibrium stationary state of a harmoniccrystal with alternating massesKannan V; Dhar, Abhishek; Lebowitz JLPhys. Rev. E 8585858585, 041118, 2012

4 Cylindrical cellular geometry ensures fidelityof division site placement in fission yeastMishra M; Huang Y; Srivastava P; SrinivasanR; Sevugan M; Shlomovitz R; Gov N; Rao M;Balasubramanian MJournal of Cell Science

5 Textured Domains on Tense Surfaces andMembranes : Effect of Tilt and ChiralitySarasij RC; Srivastava P; Rao MPhys. Rev. E. 8585858585, 041920, 2012

6 Evidence for the continuum in 2D causal setquantum gravitySurya, SumatiClassical and Quantum Gravity, 2929292929, 1320001,2012

7 Radial infall of two compact objects: 2.5-post-Newtonian linear momentum flux andassociated recoilMishra CKPhysical Review D, 8585858585, 104046, 2012

8 The uncertainty product of position andmomentum in classical dynamicsKarthik HS; Devi, Usha*American Journal of Physics, 8080808080, 708, 2012

9 The diffeomorphism constraint operator inloop quantum gravityVaradarajan, MadhavanJ. Phys. Conf. Ser. 360360360360360, 012009, 2012

10 Strain glass analogue in a bent-core liquidcrystal exhibiting the dark conglomeratephaseRoy, Arun; Gupta, Meenal; Radhika S;Sadashiva BK; Pratibha RSoft Matter, 88888, 3207, 2012

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11 Photoconductivity of doped hexa-alkoxytriphenylene nano composite structuresKavitha C; Avinash BS; Kumar, Sandeep;Lakshminarayanan VMaterials Chemistry and Physics 111113333333333, 2-3,635–641, 2012

12 Phase behavior of two-component lipidmembranes: Theory and experimentsKamal, Md. Arif; Pal, Antara; Raghunathan VA;Rao, MadanPhys. Rev. E., 8585858585, 051701, 2012

13 Phase behaviour of thecetyltrimethylammonium tosylate (CTAT) -water systemPal, Antara; Mary, Rose; Raghunathan VAJournal of Molecular Liquids

14 Phase behavior of phospholipid-phytosterolmembranesKamal, Md. Arif.; Raghunathan VASoft Matter, 88888, 8952, 2012

15 Modulated phases of phospholipid bilayersinduced by tocopherolsKamal, Md. Arif; Raghunathan VABiochem. Biophys. Acta, 11111888881111188888, 2486, 2012

16 Effect of ring-substituted oxysterols on thephase behavior ofdipalmitoylphosphatidylcholine membranesKamal, Md. Arif; Raghunathan VAEuro. Biophys. J.

17 Achiral bent-core azo compounds: effect ofdifferent types of linkage groups and theirdirection of linking on liquid crystallinepropertiesNagaveni NG; Roy, Arun; Prasad, VeenaJ. Mater. Chem, 2222222222, 8948-8959, 2012

18 Galactic winds driven by cosmic-ray streamingUhlig M; Pfrommer C; Sharma, M; Nath BB;Ensslin TA; Springel, VMonthly Notices of Royal AstronomicalSociety, 423423423423423, 2374, 2012

19 Simulation of radiation driven winds from discgalaxiesChattopadhyay, Indranil; Sharma, Mahavir;Nath BB; Ryu, DongsuMonthly Notices of Royal AstronomicalSociety, 423, 423, 423, 423, 423, 2153, 2012

20 Energy deposition profiles and entropy ingalaxy clustersChaudhuri A; Nath BB; Manjumdar,SubhabratraAstrophysical Journal, 2012

21 The roles of radiation and Ram Pressure indriving galactic windsSharma, Mahavir; Nath BBAstrophysical Journal 750750750750750,55,2012

22 Pulsed Radio Emission from the Fermi-LATPulsar J1732-3131: Search and A PossibleDetection at 34.5 MHzMaan, Yogesh; Aswathappa HA;Deshpande AAMonthly Notices of the Royal AstronomySociety, 2012

23 Unstable m = 1 modes of counter-rotatingKeplerian discsGulati, Mamta; Saini, Tarun Deep; Sridhar SMonthly Notices of the Royal AstronomicalSociety, 424242424244444, 348, 2012

24 A new layout optimization technique forarrays, applied to the MWABeardsley AP; Hazelton BJ; Morales MF;Cappallo RC; Goeke R; Emrich D; Lonsdale CJ;Arcus W; Barnes D; Bernardi G; Bowman JD;Bunton JD; Corey, BE; Deshpande AA;deSouza L; Gaensler BM; Greenhill LJ; HerneD; Hewitt, JN; Kaplan, DL; Kasper JC; KincaidBB; Koeing R; Kratzenberg E; Lynch MJ;McWhirter SR; Mitchell DA; Morgan E; OberoiD; Ord SM; Pathikulangara, J; Prabu T;Remillard RA; Rogers AE E; Roshi A; Salah JE;Sault RJ; Udaya Shankar N; Srivani KS;Stevens J; Subrahmanyan R; Tingay SJ; WaythRB; Waterson M; Webster RL; Whitney AR;Williams A; Williams CL; Wyithe JSBMonthly Notices of the Royal AstronomySociety

25 A new layout optimization technique forinterferometric arrays and the final MWAantenna layoutBeardsley AP; Deshpande AA; Prabu T; UdayaShankar N; Srivani KS; Subrahmanyan RMonthly Notices of the Royal AstronomySociety

26 Single-pulse analysis of PSR B1133+16 at8.35 GHz and carousel circulation timeHonnappa, Sneha; Lewandowski, Wojciech;Kijak, Jaroslaw; Deshpande AA; Gil, Janusz;Maron, Olaf; Jessner, AxelMonthly Notices of the Royal AstronomySociety, 42 42 42 42 4211111, 1996, 2012

27 Neutrinos from Decaying Muons, Pions,Kaons and Neutrons in Gamma Ray BurstsMoharana, Reetanjali; Gupta, NayantaraAstroparticle Phys. 36,36,36,36,36, 195, 2012

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28 Spectrum and ionization rate of low energyGalactic cosmic raysNath BB; Nayantara, Gupta; Peter L BiermannMonthly Notices of the Royal AstronomySociety

29 Counter-rotating stellar discs around amassive black hole: self-consistent, time-dependent dynamicsJihad Touma R; Sridhar SMonthly Notices of the Royal AstronomySociety, 423423423423423, 2083, 2012

30 Mean field dynamo action in renovatingshearing flowsKolekar S; Subramanian K; Sridhar SPhysical Review E, 8686868686, 026303, 2012

In ConfIn ConfIn ConfIn ConfIn Conference Prerence Prerence Prerence Prerence Proceedingsoceedingsoceedingsoceedingsoceedings

1 OH Maser sources in W49N: probingdifferential anisotropic scattering withZeeman pairsDeshpande AA; Goss WM; Mendoza-Torres JEProceedings IAU Symposium No. 287, 2012,Cosmic masers - from OH to H0

2 Binary systems: implications for outflows &periodicities relevant to masersSingh, Nishant K; Deshpande AAProceedings IAU Symposium No. 287, 2012,Cosmic masers - from OH to H0

3 Unique collections at Raman ResearchInstitute Library: a case studyBenegal, VrindaNational Conference Soference-2011, TataConsultancy Services, Bangalore, 15 October2011

4 Open access digital institutional repository ofRaman Research InstituteBenegal, Vrinda57th All India Library Conference Proceedings,St. Agnes Centre for Post Graduate Studiesand Research, Mangalore, 23-25 February2012; ISBN: 81-85216-45-6

5 Digital information services and products: acase of Raman Research Institute, BangaloreMeera BM; Manjunath M; Savanur, KiranNational seminar on Content Managementand Libraries: new vistas for harnessinginformation, Kerala Library Association, 14 –16 July 2011

6 Imprints collection: a cyberscholarship of RRIMeera BM; Savanur, Kiran; Manjunath MSoference 2011: a social conference, TataConsultancy Services, 15 October 2011

7 H-index as research performance indicator: astudy at Raman Research InstituteMeera BMNational Workshop on using different metricsfor assessing research productivity by IndianStatistical Institute, New Delhi, 16 – 17February 2012

8 Tuning the amphiphile-DNA condensatestructure with strongly binding counterionsRadhakrishnan AV; Ghosh, Sajal; Pabst,Georg; Raghunathan VA; Sood, AjayProc. Natl. Acad. Sci., 2012

9 SU(2) gauge theory of gravity with topologicalinvariantsSengupta, SandipanJ. Phys.: Conf. Ser. 360360360360360, 012024, 2012

Book chaptBook chaptBook chaptBook chaptBook chaptererererersssss

1. Methods to reduce power consumption ofliquid crystal displaysChapter in the book Progress in LC Scienceand Technology, in Honor of Prof Kobayashi80th BirthdayRuckmongathan TNWorld Scientific Publishing Co. (WSPC) underthe Liquid Crystal Book Series around Q3/2012

2. Directions in Causal Set Quantum GravitySurya, SumatiRecent Research in Quantum Gravity NovaScience Pub. Inc., Hauppauge, USA, 2012

3. Chemistry of Columnar Liquid Crystals inLiquid Crystalline SemiconductorsKumar, SandeepCanopus Academic Publishing Ltd., Bristol,UK.

________________________________________

* denotes co-authors who do not belong to RRI+ denotes Visiting Professors of RRI

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APPENDIX 2Conferences attended

Abhishek Dhar Workshop on Fourier LawField’s Institute, Toronto4 – 8 April 2011

Workshop on Foundations andApplications of Non-equilibriumStatistical MechanicsNordic Institute for Theoretical PhysicsStockholm19 – 30 September 2011

Rutgers University, USA1 – 12 October 2011

Tokyo University, Japan14 – 26 October 2011

International Centre for TheoreticalSciences, Bangalore14 November 2011

Conference on Concepts andChallenges in Astronomy andAstrophysicsSundarban Mahavidyalaya, West Bengal24 – 25 November 2011

NameNameNameNameName ConfConfConfConfConferences atterences atterences atterences atterences attended /ended /ended /ended /ended / Title of paper / talkTitle of paper / talkTitle of paper / talkTitle of paper / talkTitle of paper / talkInstitutions visitInstitutions visitInstitutions visitInstitutions visitInstitutions visitededededed

Heat conduction in disorderedharmonic lattices with energyconserving noise (invited)

Current fluctuations and largedeviation functions in heat transport(invited)

Current fluctuations and largedeviation functions in heat transport

Current fluctuations and largedeviation functions in heat transport(invited)

Brownian motion (invited)

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DST-SERC School on Nonlinear DynamicsIndian Institute of Science Education andResearch, Pune19 – 23 December 2011

ICTS school on Nonequilibrium PhysicsIndian Institute of Science Education andResearch, Kolkata3 – 4 January 2012

6th International Conference on UnsolvedProblems on Noise and FluctuationsSaha Institute of Nuclear Physics, Kolkata20 – 24 February 2012

TIFR-CAM, Bangalore20 March 2012

School on Statistical PhysicsRaman Research Institute Bangalore26 March – 7 April 2012

Anagha Datar Tata Institute of Fundamental Research,MumbaiNovember 2011

Indian Institute of Science Education andResearch, Pune20 – 26 February 2012

Andal Narayanan Indian Institute of Science Education andResearch, Pune28 March – 15 April 2011

University of Calgary, CanadaAugust 2011 – July 2012

Anirban Polley Conference on Dynamics of PhaseTransformationsJawaharlal Nehru Centre for AdvancedScientific Research, Bangalore28 – 30 November 2011

Conference on An Interdisciplinary Approachto Soft Matter and Biological PhysicsIndian Association for the Cultivation ofScience, Kolkata2 – 3 December 2011

Linear-response theory (five lectures)

Current fluctuations in heat transport(invited)

Additivity principle in three-dimensionaldeterministic systems

Heat flow and current fluctuations inharmonic systems with Langevin dynamics

Introduction to stochastic processes anddynamical systems (three lectures)

II125

Annual MeetNational Centre for Biological SciencesBangalore2 – 3 January 2012

JAKS School: Unifying Concepts in MaterialsJawaharlal Nehru Centre for AdvancedScientific Research and National Centre forBiological Sciences, Bangalore30 January – 8 February 2012

School on Statistical PhysicsRaman Research Institute, Bangalore26 March – 7 April 2012

Anjan Roy ICTS School on Random Matrix Theory andApplicationsIndian Institute of Science, Bangalore17 January – 1 February 2012

3rd School on Statistical PhysicsRaman Research Institute, Bangalore26 March – 7 April 2012

Arnab Pal ICTS International School on Topology inQuantum MatterIndian Institute of Science, Bangalore29 June – 13 July 2011

ICTS International School and Conferenceon Random Matrix TheoryIndian Institute of Science, Bangalore17 January – 1 February 2012

3rd School on Statistical PhysicsRaman Research Institute, Bangalore26 March – 7 April 2012

Arun Roy National Conference on Materials forAdvanced Technology, Gwalior27 – 29 February 2012

Avinash BS Kyushu Institute of Technology, Japan12 November 2011

Avinash Deshpande Radio Astronomy School 2011National Centre for Radio Astronomy, Pune3 – 6 July 2011

Aciral fluid lamellar phases with triclinicsymmetry (invited)

Antennas and receivers (2 lectures)

II126

The URSI GA and Scientific Symposium ofInternational Union and Radio Science,Turkey13 – 20 August 2011

IAU Symposium 2012 Cosmic Masers – fromOH to H0Stellenbosh, South Africa29 January – 3 February 2012

SKA-SA, South Africa4 – 11 February 2012

Biman B Nath Max Planck Institut for AstrophysicsGarching19 March – 15 June 2011

Instut Astrophysique de Paris, France21 – 23 April 2011

University of Leiden, The Netherlands2 – 4 May 2011

Scuola Normale Superiore of Pisa, France23 – 24 May 2011

Nehru Planetarium, New Delhi26 July 2011

Astrophysics SeminarIndian Institute of Science8 August 2011

Galaxy Forum 2012Jawaharlal Nehru Planetarium9 August 2011

IIA Theoretical Astrophysics Group MiniWorkshop on Cosmology & GalaxiesIndian Institute of Astrophysics28 November 2011

Conference on Dust in AstrophysicsAssam University31 January – 2 February 2012

RRI-GBT multi-band receiver and pulsaremission cone tomography

1. OH maser sources in W49N: probing differential anisotropic scattering with Zeeman pairs2. Binary systems: implications for outflows and periodicities relevant to masers

1. Radio frequency interference: to avoid or attack2. The 4 Cs: coherence, correlation, convolution, calibration

Galactic outflows with thermal andradiation pressure

Galactic outflows with radiation pressure

Galactic outflows

Stars in the hood; the story of ourneighbourhood stars

Galactic outflows with radiation pressure

Our universe (invited)

Galactic winds and the intergalacticmedium (invited)

Dust driven outflows from galaxies (invited)

II127

National Space Science SymposiumSri Venkateswara University, Tirupati14 – 17 February 2012

Biswajit Paul Be X-ray Binaries WorkshopUniversity of Valencia Spain11 – 14 July 2011

Conference on Exploring the COSMOSNorth Bengal University, Darjeeling15 – 16 December 2011

Astrosat WorkshopIndian Institute of Space Science andTechnology, Trivandrum9 – 12 January 2012

Advanced Workshop on X-ray TimingInter University Centre for Astronomy &Astrophysics, Pune23 – 28 January 2012

Winter School on High Energy Astrophysics:Accretion onto compact objectsHarishchandra Research InstituteAllahabad6 – 18 February 2012

Conference on Advances in AstroparticlePhysics and Cosmology 2012, Darjeeling7 – 12 March 2012

Chaitra Shreepad Hegde School on Topology and Quantum MatterIndian Institute of Science, Bangalore29 June – 13 July 2011

School on Random Matrix TheoryIndian Institute of Science, Bangalore17 January – 1 February 2012

School on Statistical PhysicsRaman Research Institute, Bangalore26 March – 7 April 2012

Cosmology – recent advances andchallenges ahead

1. Quasi periodic oscillations in high magnetic field accretion powered pulsars (two lectures)2. Intensity and energy dependent profiles of transient HMXB pulsars3. Orbital evolution and apsidal motion of HMXBs

An overview of neutron stars

1. An overview of Astrosat2. Fundamentals of X-ray Timing Analysis

1. Astrosat LAXPC2. X-ray timing with LAXPC

X-ray Binaries (series of lectures)

High Energy Astrophysics with Astrosat andongoing projects for future missions

II128

Chandrakant Mishra 7th International Conference on Gravitationand Cosmology, Goa14 – 19 December 2011

Chandreyee Maitra Advanced Workshop on X-ray timingInter University Centre for Astronomy &Astrophysics, Pune23 – 28 January 2012

Winter School on High Energy AstrophysicsSymposiumHarishchandra Research Institute,Allahabad18 February 2012

Debasish Saha International Workshop on Soft MatterChemistry, Raman Research Institute,Bangalore9 – 11 November 2011

International Conference on Dynamics ofPhase TransitionJawaharlal Nehru Centre for AdvancedResearch, Bangalore28 – 30 November 2011

SERC School and National Symposium onRheology and Complex FluidsIndian Institute of Technology, Guwahati3 – 7 January 2012

IUTAM Symposium on Mobile ParticulateSystemsHotel Lalith Ashok, Bangalore23 – 27 January 2012

Deepak Pandey University of Pisa, Italy17 – 21 June 2011

Institut d’Optique, France22 June – 21 July 2011

University of Basel, Switzerland15 – 18 July 2011

Dhason A 17th National Seminar of ISSG ‘Glassmoulds/devices for chemical analysis in NRindustry’Rubber Research Institute of India, Kerala2 – 3 May 2011

Nonspinning inspiralling compact binariesin quasi-circular orbits

Pulse phase resolved spectroscopy ofHMXB accretion powered pulsars

Pulse phase resolved spectroscopy ofHMXB accretion powered pulsars

Caging dynamics in colloidal glasses oflaponite

Caging dynamics in colloidal glasses oflaponite

Quantum walk of light in frequency spaceand its controlled dephasing

Implementation of quantum algorithms andquantum logic gates using ultracold atomand light

1. A versatile multifunctional glass adapter for use in chemistry laboratories2. Structure of glass and how does it break

II129

Dwarakanath KS The Path to SKA-low WorkshopInternational Centre for Radio AstronomyResearch, Western Australia6 – 9 September 2011

National Center for Radio AstrophysicsPune10 November 2011

Inter University Center for Astronomy andAstrophysics, Pune11 November 2011

Geetha S Panel Discussion on Challenges ahead oflibrarians in serving its readersTripuravasini Auditorium, Bangalore7 September 2011

Conference Infovision 2011 – Data forDifferentiationInfosys, Bangalore24 September 2011

Girish BS The Path to SKA-low WorkshopInternational Centre for Radio AstronomyResearch, Western Australia6 – 9 September 2011

The SKA India Meet 2011National Centre for Radio Astronomy, Pune10 – 11 November 2011

Radio Astronomy Centre, Ooty12 January 2012

Hema Ramachandran Tata Institute of Fundamental ResearchMumbai7 September 2011

Mumbai University, Mumbai8 September 2011

University of Hyderabad, Hyderabad31 January 2012

Faculty Development Program on CognitiveScience and Brain Computer InterfaceM.S. Ramaiah Institute of TechnologyBangalore26 March 2012

Cluster halos and relics at low frequencies– current status and future prospects(invited)

Current activities and future plans in low-frequency astronomy

A 144-element receiver system for the RRIAA demonstrator

Analog receiver systems for ORT upgrade –the road traversed

Quantum walks

Atoms and light performing quantum walks

The classical analogue of the non-localAharanov-Bohm effect

Brain computer interfaces

II130

SERC School on Laser Physics andTechnologyRaja Ramanna Centre for AdvancedTechnology, Indore28 March 2012

Iyer BR Bangalore University, Bangalore19 April 2011

Institute for Plasma Research, Ahmedabad2 May 2011

Jawaharlal Nehru Planetarium, Bangalore31 May 2011

Annual GWIC MeetingCardiff University, United Kingdom10 July 2011

Cardiff University, United Kingdom1 – 15 July 2011

Amaldi 9Cardiff University, United Kingdom13 – 17 July 2011

Indian Institute of Science, Bangalore18 August 2011

Hind High Vacuum, Bangalore18 August 2011

IndIGO Meeting on LIGO-IndiaHomi Babha Centre for Science EducationMumbai19 August 2011

Institute for Plasma Research, Ahmedabad17 August 201119 October 2011

Tata Institute of Fundamental ResearchMumbai19 August 201120 October 2011

Raja Ramanna Centre for AdvancedTechnology, Indore23 August 20111 – 3 March 2012

Light in random media

Gravitational waves: A century of waiting

The search for gravitational waves: acentury of waiting

Einstein’s Theory of Gravitation andGravitational Waves, I, II

The case for IndIGO membership of GWIC(invited)

Parametrized tests of post-Newtoniantheory using Advanced LIGO and EinsteinTelescope

IndIGO and LIGO-India

II131

Indian Institute of Technology, Gandhinagar12 September 2011

EGO-IndIGO meeting on GWInter University Centre for Astronomy &Astrophysics, Pune1 – 2 November 2011

Astronomy Mega-Projects under XIIth PlanMeetingDepartment of Science and TechnologyDelhi21 November 2011

Mid-Term Review MeetingIndo French Centre for Promotion ofAdvanced Research (CEFIPRA), Udaipur22 November 2011

9th International Conference on Gravitationand Cosmology, Goa14 – 19 December 2011

ICTS Workshop on Gravitational WavesInter University Centre for Astronomy &Astrophysics, Pune20 – 22 December 2011

Karnataka State Disaster ManagementCentre, Bangalore30 December 2011

IndIGO meeting on LIGO-IndiaInstitute for Plasma Research, Ahmedabad3 February 2012

Indian Institute of Science Education andResearch, Pune14 February 2012

Inter University Centre for Astronomy &Astrophysics, Pune1 – 2 April 201122 – 23 September 20116 – 8 October 201121 – 22 October 201119 – 22 December 201113 February 20124 – 6 March 201217 March 201218 – 24 March 2012

IndIGO and LIGO-India, Introductoryremarks (invited)

Gravitational waves from binary black holes– mid term report

Nonspinning inspiralling compact binariesin quasi circular orbits: 2.5 PN linearmomentum loss and associated recoil

LIGO-India: current status (invited)

LIGO-India: current status

Gravitational waves: when theory metexperiment

II132

Jacob Rajan National Workshop on Cloud ComputingCentre for Development of AdvancedComputing, Knowledge Park21 May 2011

Joseph Samuel Chennai Mathematical Institute, Chennai16 – 17 August 2011

Indian Institute of Science Education andResearch, Trivandrum3 – 8 January 2012

Indian Institute of Science, Bangalore12 January 2012

Chennai Mathematical Institute, Chennai28 February 2012

Jyothi S 3rd International Conference on CurrentDevelopments in Atomic, Molecular, Opticaland Nano Physics 2011University of Delhi14 – 16 December 2011

Kanhaiya Lal Pandey ASI Symposium (ICCGF)Indian Institute of Science Education andResearch, Mohali5 November 2011

Karthik HS International Workshop on QuantumInformationHarishchandra Research InstituteAllahabad20 – 26 February 2012

Lakshminarayanan V Oracle Science Foundation TalkBGS National Public School, Bangalore10 June 2011

12th IDE-NICE ConferenceDezaifu, Japan20 October 2011

Graduate School of Biological and LifeSciencesKyushu Institute of Technology, Japan24 October 2011

The nonlocal Pancharatnam phase

Atom interferometry and the gravitationalred shift

The nonlocal Pancharatnam phase in twophoton interferometry

Atom interferometry and the gravitationalred shift

Cavity mode emission from cold trappedatoms

Constraints on primordial magnetic fieldsusing cosmic shear statistics

Classical uncertainties

Seeing atoms and molecules (invited)

Electrical conductivity studies on discoticliquid crystals and composites

Electrochemistry of nanomaterials forbiosensors and catalysis (invited)

II133

International Workshop on Soft MatterChemistryRaman Research Institute10 November 2011

1. Physics Convention2. Convergence in ChemistrySri Sathya Institute of Higher Learning,Prasanthi Nilayam, Bangalore1. 6 August 20112. 28 November 2011

Central Electrochemical Research InstituteKaraikudi7 – 8 February 2012

First International Symposium on Physicsand Technology of SensorsCentre for Materials for ElectronicsTechnology, Pune7 March 2012

UGC Faculty Improvement ProgrammeBangalore University, Bangalore14 March 2012

Laxmi Kishore Sagar International Workshop on Soft MatterChemistryRaman Research Institute9 – 11 November 2011

Lakshmi Saripalli Netherlands Institute for Radio AstronomyThe Netherlands1 September–30 November 2011

Radboud Universiteit, The Netherlands8 November 2011

LOFAR Magnetism Key Science ProjectWorkshopIsituto di Radioastronomia, Bologna24 – 25 November 2011

University of Western Australia, Australia30 January – 29 February 2012

Electrochemical studies in self-organizedsoft matter systems (invited)

1. Electrochemistry of nanomaterials for biosensors (invited)2. Disc like liquid crystals for molecular electronics and photonic applications (invited)

Electrochemistry of nanomaterials forbiosensors and catalysis

Mechanism of electrochemical sensors(invited)

1. Electrochemical methods in biosensing and catalysis2. Scanning probe microscopy and its applications in chemistry

On growth and form: radio galaxymorphologies and the ATLBS radiocontinuum survey

Towards probing AGN lifecycles: Radiogalaxy morphologies and the ATLBS radiocontinuum survey

Aspects of radio galaxies and lifecycles(invited)

II134

Madhavan Varadarajan Loops 11CSIC, Spain23 – 28 May 2011

St. Stephen’s College, New Delhi21 – 28 October 2011

7th International Conference on Gravitationand Cosmology, Goa14 – 19 December 2011

Mahavir Sharma Indian Conference on Cosmology and GalaxyFormation 2011Indian Institute of Science Education andResearch, Mohali5 November 2011

Mahesh Kumar Varia International Workshop on Soft MatterChemistryRaman Research Institute9 – 11 November 2011

18th National Conference on Liquid CrystalsNorth-eastern Regional Institute of Scienceand Technology, Itanagar15 – 17 November 2011

Manjunath M National Seminar on Content Managementand Libraries: New Vistas for HarnessingInformationKerala Library AssociationThiruvananthapuram14 – 16 July 2011

Workshop on Statistical Analysis ofResearch DataInstitute for Management DevelopmentMysore3 – 4 February 2012

Workshop on Statistical Methods forCommunication ScienceKarnataka University, Dharwad27 February – 1 March 2012

Mayuri S Winter School on Astroparticle PhysicsBose Institute, Kolkata17 – 29 December 2011

Advanced Workshop on X-ray TimingInter University Centre for Astronomy &Astrophysics, Pune23 – 28 January 2012

The diffeomorphism constraint in loopquantum gravity

Towards a consistent quantum dynamicsfor canonical loop quantum gravity

Galactic winds

1. T-shaped unsymmetrical azoester based substituted biphenyl2. Hexasubstituted truxene with branched alkyl peripheral spacers

T-shaped unsymmetrical azoester basedmesogenic dimers

II135

Winter School on High Energy AstrophysicsHarishchandra Research InstituteAllahabad6 – 18 February 2012

Meena MS Apex Technical Seminar Cirrus Logic/ApexMicrotechnology, Bangalore19 September 2011

Conference NIDays 2011Nimhans Convention Center, Bangalore14 October 2011

Technical Seminar ADWTS 2012Agilent Technologies, Bangalore17 April 2012

Meera BM National Seminar on Content Managementand Libraries: new vistas for harnessinginformationKerala Library AssociationThiruvananthapuram14 – 16 July 2011

SoFerence 2011Tata Consultancy Services, ITPL, Bangalore15 October 2011

NKRC Nodal Officers MeetingNational Institute of Oceanography, Goa18 – 20 October 2011

Workshop on Open Access to AcademicResearchIndian Institute of Science, Bangalore2 November 2011

National Workshop on using differentmetrics for assessing research productivityIndian Statistical Institute, New Delhi16 – 17 February 2012

Nagaraj MN Workshop on Training on ContentManagement using Open Source Tool-DrupalNational Aerospace Laboratories, Bangalore19 – 21 April 2011

Digital Information services and products: acase of Raman Research Institute

Imprints collection: a cyberscholarship ofRRI

H-Index as research performance indicator:A study at Raman Research Institute

II136

National Conference on Information LiteracyCompetencies for Higher Learning andResearchTumkur University, Tumkur21 – 22 October 2011

Workshop on SPSS for Data AnalysisMangalore University, Mangalore19 November 2011

Nazma Islam Syeda Advanced Workshop on X-ray TimingInter University Centre for Astronomy &Astrophysics, Pune23 – 28 January 2012

Winter School on High Energy AstrophysicsSymposiumHarish Chandra Research InstituteAllahabad18 February 2012

Nithyanandan Bi-annual MWA Project MeetingThyagarajan University of Melbourne, Australia

5 – 8 December 2011

Workshop on MWA Data AnalysisAustralia National University, Australia7 – 9 February 2012

Curtin University, Australia14 February 2012

Prabu T MWA MeetingMassachusetts Institute of Technology, USA7 June 2011

CASPER Workshop 2011National Centre for Radio AstrophysicsPune13 – 14 October 2011

Bi-annual MWA Project MeetingUniversity of Melbourne, Australia7 – 8 December 2011

Pragya Srivastava Annual MeetNational Centre for Biological SciencesBangalore2 – 3 January 2012

Implementation of Library 2.0 technologyto information literacy

Effect of variability of X ray binaries on X-ray luminosity functions for our galaxy

Effect of variability of X ray binaries on Xray luminosity functions for our galaxy

A study of foreground contamination in theEoR window

1. Study of foreground contamination of the EoR2. A search for radio transients and variables in the FIRST survey

Digital receiver enhancements – a statusupdate

1. MWA digital receiver development at RRI2. FPGA based projects at RRI – a review

1. Digital receiver – an update2. Thoughts on commissioning the MWA digital receiver

Patterns of actin filaments on cylindricaland spherical geometries: asters, helices,rings

II137

Patterns of active polar filaments in curvedgeometries

A novel optical fiber based force apparatus

Active mechanics of axons

Active mechanics of axons

Mechanics of living matter

Glassy nature of the dark conglomerateliquid crystalline phase (invited)

JAKS School: Unifying Concepts in MaterialsJawaharlal Nehru Centre for AdvancedScientific Research and National Centre forBiological Sciences, Bangalore30 January – 8 February 2012

Pramod Pullarkat NUS-NCBS Collaboration ExplorationMeetingNational Centre for Biological SciencesBangalore13 April 2011

Conference on Mathematics and Physics ofSoft and Biological MatterInternational Centre for Theoretical PhysicsItaly9 – 13 May 2011

University of Freiburg, Germany14 – 20 May 2011

Technical University, Munich18 May 2011

International Conference on Mathematicaland Theoretical BiologyIndian Institute of Science Education andResearch, Pune23 – 27 January 2012

Prasad VV School on Random Matrix Theory andApplicationsIndian Institute of Science, Bangalore17 January – 1 February 2012

JAKS School: Unifying Concepts in MaterialsJawaharlal Nehru Centre for AdvancedScientific Research, Bangalore30 January - 5 February 2012

School on Statistical PhysicsRaman Research Institute26 March – 7 April 2012

Pratibha R International Workshop on Soft MatterChemistryRaman Research Institute9 – 11 November 2011

II138

National Conference on Condensed MatterPhysicsBirla Institute of Technology and SciencePilani24 – 25 February 2012

Priya Rose T HCU-TIFR Discussion MeetingCentral University of Hyderabad, Hyderabad1 – 3 August 2011

DAE-BRNS National Laser Symposium-20Anna University, Chennai9 – 12 January 2012

Raghunathan A The URSI GA and Scientific Symposium ofInternational Union and Radio ScienceTurkey13 – 20 August 2011

Raghunathan VA 8th Liquid Matter ConferenceUniversity of Vienna, Austria6 – 11 September 2011

Conference on Current Topics in CondensedMatterIndian Institute of Science Education andResearch, Kolkata7 – 9 October 2011

Conference on Frontiers in PhysicsUniversity of Hyderabad, Hyderabad28 – 29 October 2011

Sixth National Symposium on Rheology ofComplex FluidsIndian Institute of Technology, Guwahati6 – 7 January 2012

Institute of Biophysics and NanosystemsResearch, Austria1 – 5 September 2011

Rajib Basak SERC School and National Symposium onRheology of Complex FluidsIndian Institute of Technology, Guwahati3 – 7 January 2012

Ranjini Bandyopadhyay Conference on Current Trends in CondensedMatter PhysicsIndian Institute of Science and EducationResearch, Kolkata9 October 2011

Layer structure stabilized gold nanosphere– smectic liquid crystal colloids (invited)

Time-resolved spectroscopy of femtosecondlaser-induced carbon plasma in the rough,medium and high vacuum regimes

1. Zero spacing interferometer to detect cosmological reionization signatures2. Observatory reports

Polymorphism of two-dimensional crystalsof oppositely charged cylindrical macroions

A novel phase of amphiphile bilayers(invited)

Electrostatic self-assembly of oppositelycharged macroions (invited)

A defect-mediated lamellar to isotropictransition of amphiphile bilayers (invited)

A disordered phase of surfactant bilayers

Effect of anionic surfactant on the jammingbehavior of triblock copolymer system

Mustard seeds shaken hard: a segregationphenomenon in a vibrated quasi two-dimensional granular column (invited)

II139

University of Tokyo, Japan18 October 2011

Toyohashi Institute of Technology, Japan20 October 2011

International Workshop on Soft MatterChemistryRaman Research Institute11 November 2011

Jawaharlal Nehru Centre for AdvancedScientific Research, Bangalore30 November 2011

Bose Institute, Kolkata3 January 2012

SERC School-cum-Symposium on theRheology of Complex FluidsIndian Institute of Technology, Guwahati6 January 2012

Indian Institute of Science, Bangalore1 February 2012

Maharani Lakshmi Ammanni CollegeBangalore6 March 2012

Ravi K Conference on New Trends in QuantumMatter with Cold Atoms and MoleculesInstituto de Fisica de Sao Carlos, Brazil4 – 14 April 2011

Institut d’ Optique, France6 January 2012

Conference on Physics with TrappedCharged ParticlesEcole de Physique des Houches, France9 – 20 January 2012

Universitat Basel, Switzerland21 January 2012

Institut fur Physik, Germany21 January – 4 February 2012

Experiments on aging soft colloidal glassesand rising Brazil nuts

Experiments on aging soft colloidal glassesand rising Brazil nuts (invited)

Rise of an intruder in a quasi 2D granularcolumn is driven by granular convection

Rising Brazil nuts in a quasi two-dimensional granular column: dynamics ofphase transformations (invited)

Convection-driven rise of an intruder in aquasi two dimensional granular bed(invited)

Rizing Brazil nuts in a quasi two-dimensional granular column: dynamics ofphase transformations (invited)

Scaling behavior in convection-driven Brazilnut effect: contemporary issues incondensed matter science (invited)

How so soft materials move when pushedreally hard (invited)

An experimental setup to study ion-atomprocesses

Collisional cooling of ions by cold atoms ina combined trap

II140

Max-Planck-Institut fur Kernphysik, Germany2 February 2012

Universistat Ulm, Germany3 February 2012

Ravi Subrahmanyan MWA MeetingMassachusetts Institute of Technology, USA5 – 8 June 2011

Pentiction Workshop on Novel Telescopesfor 21cm CosmologyDominion Radio Astrophysical ObservatoryCanada13 – 16 June 2011

The URSI GA and Scientific Symposium ofInternational Union and Radio ScienceTurkey13 – 20 August 2011

MWA Project MeetingUniversity of Melbourne5 – 8 December 2011

SKA ANZ Meeting 2012New Zealand13 – 16 February 2012

University of Western Australia, AustraliaFebruary 2012

Curtin University, AustraliaFebruary 2012

Ruckmongathan TN SID Symposium 2011Society for Information Display, USA15 – 20 May 2011

EURODISPLAY, International DisplayResearch ConferenceEcole Polytechnique, France21 September 2011

XIVth International Workshop on Physics ofSemiconductor DevicesIndian Institute of Technology, Kanpur19 – 22 December 2011

Cooling of rubidium ions by cold Rubidiumatoms in a combined trap

Cooling of rubidium ions by cold Rubidiumatoms in a combined trap

Extragalactic low surface brightness radiosky

1. Long wavelength radio science (invited)2. The Murchison Widefield Array

The Murchison Widefield Array (invited)

Gray scales by cross pairing of select anddata voltages in liquid crystal displays

Bit slice addressing and multi-bit sliceaddressing of AMLCD (invited)

Bit slice addressing and multi-bit sliceaddressing of AMLCD (invited)

II141

International Conference on Luminescenceand its ApplicationsRajiv Gandhi University of KnowledgeTechnologies, Hyderabad7 – 10 February 2012

Sadiqali Rangwala Conference on New Trends in QuantumMatter with Cold Atoms and MoleculesInstituto de Fisica de Sao Carlos, Brazil4 – 14 April 2011

EGO-IndIGO Meeting on GWInter University Centre for Astronomy &Astrophysics, Pune1 – 2 November 2011

3rd International Conference on CurrentDevelopments in Atomic, Molecular, Opticaland Nano Physics with Applications(CDAMOP-2011)University of Delhi, New Delhi14 – 16 December 2011

Topical Conference of the ISAMP-TC2012 -Laser Interaction with Atoms, Molecules andClustersUniversity of Hyderabad, Hyderabad9 – 12 January 2012

Conference on Physics with TrappedCharged ParticlesEcole de Physique des Houches, France9 – 20 January 2012

The India-UK Scientific Seminar SchemeBhuvaneshwar7 – 9 March 2012

Samim Ali International Conference on Dynamics ofPhase TransitionJawaharlal Nehru Centre for AdvancedScientific Research, Bangalore28 November 2011

SERC School and National Symposium onRheology of Complex FluidsIndian Institute of Technology, Guwahati3 January 2012

Low power, high performance liquid crystaldisplays with simple data drivers (invited)

An experimental setup to study ion-atomprocesses

Experiments with cold atoms in Fabry PerotCavity in Ultra High Vacuum

1. Collisional cooling of ions with cold atoms of equal mass2. Cavity mode emission from cold trapped atoms

From cold atoms and cold ions to coldmolecules and cold molecular ions

Collisional cooling of ions by cold atoms ina combined trap

Cold atoms, cold ions and cold molecules

Effect of electrolyte on the settling behaviorof charged colloidal particles in aqueoussuspensions

II142

JAKS School: Unifying Concepts in MaterialsJawaharlal Nehru Centre for AdvancedScientific Research, Bangalore6 February 2012

RRI School on Statistical Physics, Bangalore26 March 2012

Sandeep Kumar CRSI Zonal MeetNational Chemical Laboratory, Pune13 – 14 May 2011

University of Hyderabad, Hyderabad4 July 2011

National Symposium on Chemistry andHumanity 2011Manipal Institute of Technology, Manipal11 – 12 July 2011

BSG National Public School, Bangalore22 July 2011

Institute of Advance Study in Science &Technology, Guwahati28 July 2011

Bannari Amman Institute of TechnologySatyamangalum24 August 2011

3rd National Conference on Recent Trendsin Polymer Science and Technology 2011PSG College of Technology, Coimbatore26 – 27 August 2011

Amrita University, Coimbatore27 August 2011

19th Conference on Liquid CrystalsChemistry, Physics and ApplicationsMiedzyzdroje, Poland19 – 23 September 2011

Department of Information TechnologyDelhi18 October 2011

Effect of electrolyte on the settling behaviorof charged colloidal particles in aqueoussuspensions

Discotic decorated nanoparticles:advanced materials for organic electronics(invited)

Discotic liquid crystals as advancedmaterials for organic electronics (invited)

Liquid crystals: paradoxical states of matter(invited)

Can crystals be liquid: the fascinating worldof liquid crystals (invited)

Liquid crystals: from curiosity to commodity(invited)

Dispersion of nanoparticles in monomericand polymeric columnar liquid crystals(invited)

The fascinating world of liquid crystals(invited)

Discotic liquid crystals nanoscience(invited)

II143

18th National Conference on Liquid CrystalsNorth-eastern Regional Institute of Scienceand Technology, Itanagar15 – 17 November 2011

International Conference on Synthetic &Structural ChemistryMangalore University, Mangalore8 – 12 December 2011

National Workshop on Soft MaterialsJMJ College for Women, Tenali24 January 2012

International Conference onSupramolecules and Nanomaterials –Research and ApplicationsGujarat University, Ahmedabad6 – 8 February 2012

Symposium on Liquid Crystalline OrganicSemiconductorsTokyo Institute of Technology, Japan21 – 22 February 2012

University of Allahabad, Allahabad9 August 201112 March 2012

Material Research Society WorkshopCentre for Material Science, Allahabad12 March 2012

Sanjib Sabhapandit 5th Indo-Israeli Meeting on CondensedMatter Physics, Cochin15 – 18 October 2011

Santosh Prasad Gupta International Workshop on Soft MatterChemistryRaman Research Institute9 – 11 November 2011

18th National Conference on Liquid CrystalsNorth-eastern Regional Institute of Scienceand Technology, Itanagar15 – 17 November 2011

Somashekar R Radio Astronomy Centre, Ooty10 – 13 January 2012

Nanoparticles in columnar mesophases(invited)

Nanoparticles in columnar matrix

The art and science of liquid crystals(invited)

Incorporation of nanoparticles in thesupramolecular order of discotic liquidcrystals (invited)

Discotic liquid crystal nanocomposites: anew class of organic semiconductors(invited)

Discotics: a new class of soft materials fororganic electronics (invited)

Record statistics of continuous timerandom walk (invited)

Effect of strongly bound species on thephase behavior of a cationic surfactant

II144

Sridhar S American University of Beirut, Lebanon6 – 30 April 2011

American University of Beirut, Lebanon4 July – 5 August 2011

Indian Institute of Science Education andResearch, Mohali30 January – 3 February 2012

Srinivasa HT International Workshop on Soft MatterChemistry 2011Raman Research Institute, Bangalore9 – 11 November 2011

Symposium on New Developments in NMRand International Conference of NationalMagnetic Resonance Society of IndiaIndian Institute of Science, Bangalore5 – 8 February 2012

Srivani KS The Path to SKA-low WorkshopInternational Centre for Radio AstronomyResearch, Western Australia6 – 9 September 2011

Suman Gaurab Das School on Random Matrix Theory andApplicationsIndian Institute of Science, Bangalore17 January – 1 February 2012

School on Statistical PhysicsRaman Research Institute, Bangalore26 March – 7 April 2012

Sumati Surya University of California, USA17 May 2011

McGill University, Canada8 September 2011

7th International Conference on Gravitationand Cosmology, Goa14 – 19 December 2011

Indian Institute of Astrophysics, Bangalore24 February 2012

MHD turbulence (3 lectures)

1. Interstellar, interplanetary and MHD turbulence2. Fluid turbulence

Acid and ester functionalized triphenylenediscotics: synthesis and mesomorphiccharacterization

Constructing a dynamics for causal setquantum gravity

Results in 2D causal set quantum gravity

2D causal set quantum gravity on thecomputer

Phenomenology from quantum gravity: abrief introduction to causal set theory

II145

Supurna Sinha St. Joseph’s College Post Graduate CentreBangalore29 July 2011

Poorna Learning Center, BangaloreNovember 2011

Indian Institute of Science Education andResearch, Trivandrum6 January 2012

Workshop on Weaves of Waves: Physics ofMusicRaman Research Institute, Bangalore18 January 2012

3rd RRI School of Statistical PhysicsRaman Research Institute, Bangalore26 March – 7 April 2012

Swamynathan K Kyushu Institute of Technology, Japan14 November 2011 – 31 January 2012

Tridib Ray EGO-Indigo MeetingInter University Centre for Astronomy &Astrophysics, Pune1 – 2 November 2011

3rd International Conference on CurrentDevelopments in Atomic, Molecular, Opticaland Nano Physics 2011University of Delhi, New Delhi14 – 16 December 2011

Udaya Shankar N Conference on Understanding Galactic andExtragalactic Foregrounds: A road tosuccess for cosmological experimentsCroatia26 May 2011

MWA Project MeetingMIT Kavli Institute for Astrophysics andSpace Research USA5 – 8 June 2011

Workshop on Novel Telescopes for 21 CmCosmologyDominion Radio Astrophysical ObservatoryCanada15 June 2011

Order out of disorder: an introduction tosoft matter physics

Light

Nonlocal Pancharatnam phase in twophoton interferometry

Cavity mode emission from cold trappedatoms

Effect of the three dimensional pointspread function on the statistical detectionof EoR

Imaging the EoR

Limitations from foreground contaminationand imaging algorithms

II146

MWA Project MeetingUniversity of Melbourne, Australia5 – 8 December 2011

Aarohana Science FestivalBMS College for Women, Bangalore24 February 2012

Venkata Jagadeesh Conference on Current Trends inRachuri Nanoscience and Technology

National Institute of Technology, Warangal23 – 24 December 2011

Conference on Interfaces between ChemicalSciences and TechnologiesNational Institute of Technology, Warangal29 – 30 December 2011

Vijayaraghavan D International Workshop on Soft MatterChemistryRaman Research Institute11 November 2011

Vrinda J Benegal Workshop on Web of Science 5.2Raman Research Institute12 May 2011

Panel Discussion on Challenges Ahead ofLibrarians in Serving its ReadersTripuravasini Auditorium, Bangalore7 September 2011

SoFerence 2011Tata Consultancy Services, ITPL, Bangalore15 October 2011

Workshop on Open Access to AcademicResearchIndian Institute of Science, Bangalore2 November 2011

57th All India Library ConferenceSt. Agnes Centre for Post Graduate Studiesand Research, Mangalore23 – 25 February 2012

Yashodhan Hatwalne International Workshop on Soft MatterChemistryRaman Research Institute9 – 11 November 2011

Cosmic distance ladder

Magnetic susceptibility studies on micelles,vesicles and bicelles (invited)

Structure of twist grain boundary phases(invited)

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APPENDIX 3Colloquia

NameNameNameNameName TitleTitleTitleTitleTitle DatDatDatDatDateeeee

Amit Apte Data assimilation – interplay between 19.4.2011TIFR Centre for Applicable nonlinearity and statisticsMathematics, Bangalore

Sandeep Menon Perinchery Diagnostic potential of autofluorescence: 2.5.2011Macquarie University an explorative study with human urine,Australia stem cells and bacteria

Sandipan Sengupta Quantum realizations of Hilbert-Palatini 2.5.2011Institute of Mathematical second-class constraintsSciences, Chennai

Priya Rose T Design and characterization of photonic 11.5.2011Universita di Napoli quasi-crystals for the microwave to“Federico II” optical regimeItaly

Satya Sudhakar Yedlapalli The line spectral frequency model of a finite 20.5.2011Indian Institute of Science length sequence and its applicationsBangalore

Sanjay Gupta Dimensional and temperature dependence of 24.05.2011Bose Institute metal-insulator transition in correlated andKolkata disordered systems

III148

Harshal Bhadkamkar Collective properties of X-ray binary 24.05.2011Tata Institute of populations in nearby galaxiesFundamental Research, Mumbai

Dana Z Anderson Atomtronics, atom chips and the microwave 26.05.2011University of Colorado oscillatorBoulder, USA

Ravi Chandra V A memory saving algorithm for computing 27.05.2011Israel Institute of Technology eigenvalue approximations of quantum systemsIsrael

Jayan Thomas Advanced polymers for 3D telepresence 30.05.2011University of Arizona and energy conversionUSA

Gopal NO Visible light active nanoparticles for 31.05.2011National Dong Hwa environmental purificationUniversity, Taiwan

Urbasi Sinha Applications of quantum optics to 31.05.2011University of Waterloo quantum mechanics and quantumCanada information processing

Abhik Ghosh Characterizing the foregrounds for red 13.06.2011Indian Institute of Technology shifted 21-cm HI signal: GMRT 150 MHzKharagpur & 610 MHz observations

Archan Dey Supramolecular nano materials: Inspiration 15.06.2011Eindhoven University from crystal engineering and biomineralizaionof TechnologyThe Netherlands

Iyer BR An introduction to general relativity and 27.06.2011Raman Research Institute gravitational waves I, IIBangalore

Chandrashekar CM Quantum walk with spatial, temporal and 28.06.2011Institute of Mathematical fluctuating disordered operationsSciences, Chennai

Priyam Das Dynamics of Bose-Einstein condensates: 01.07.2011Indian Institute of Science A mean-field approachEducation and ResearchKolkata

Arvind Ayyer An exactly solvable open reaction-diffusion process 01.07.2011UC Davis, USA

Sujoy Kumar Modak Quantum tunneling and thermodynamic 11.07.2011S.N. Bose National Centre approach to black hole entropyfor Basic Sciences, Kolkata

III149

Srinivas Sridhar Controlling light with nanoscale 12.07.2011Northeastern University negative metamaterialsUSA

Rema Krishnaswamy Shear thickening in fractal aggregates 12.07.2011Jawaharlal Nehru Centre for of carbon nanotubesAdvanced Scientific ResearchBangalore

William Clark Ultra pulse lasers and system development 19.07.2011Clark-MXR Inc. at Clark-MXR Inc.USA

Sandeep Krishna Counting genomes: the lysis-lysogeny 26.07.2011National Centre for decision in temperate bacteriophageBiological Sciences, Bangalore

Seshadri TR CMB as a probe for cosmic magnetic fields 29.07.2011University of Delhi, Delhi

Arundati Dasgupta Measuring quantum gravity 04.08.2011University of LethbridgeCanada

Srivathsan Vasudevan Monitoring of individual biological 11.08.2011National Technical University cells using photothermal response andSingapore photothermal imaging techniques

Indranil Chattopadhyay Effect of composition and equation of 12.08.2011Aryabhatta Research Institute state on relativistic fluidsof Observational Sciences, Nainital

Onuttom Narayan Curvature of finite graphs and its consequences 17.08.2011University of California, USA

Deepshika Jaiswal Nagar Magnetocaloric effect and magnetic 17.08.2011Goethe Universitat, Germany cooling near a field-induced quantum-critical point

Prem Kiran P Propagation of ultrafast laser pulses 26.08.2011University of Hyderabad under tight focusing conditionsHyderabad

Mahadevan L On growth and form: geometry, physics 26.08.2011Harward University, USA and biology

Arunima Banerjee Vertical structure of disk galaxies and 26.08.2011Indian Institute of Science their dark matter halosBangalore

Anders Kastberg Experimental demonstration of the 29.08.2011Universite Nice Sophia Pancharatnam phase in intensity interferometryAntipolis, France and quantum information at University of Nice

III150

Nampoori VPN Bionanotechnology: tools and applications 06.09.2011Cochin University of Scienceand Technology, Cochin

Paramita Barai Simulating supermassive black hole accretion: 09.09.2011University of Nevada spherical flow to cold clumps and hot bubblesUSA

Subhasish Dutta Gupta 25 years of plasmonics and nano-optics at 16.09.2011University of Hyderabad University of HyderabadHyderabad

Subhasis Maity Dye sensitized photo electrochemical cell as 20.09.2011Jadavpur University organic photovoltaicKolkata

Sourav Haldar Monitoring orientation and dynamics of 26.09.2011Centre for Cellular membrane-bound melittin utilizing dansyl fluorescenceand Molecular BiologyHyderabad

Hari Dass ND Neutrinos breaking the light barrier? 13.10.2011Chennai MathematicalInstitute, Chennai

Dan Werthimer The collaboration for radio astronomy 17.10.2011University of signal processing and electronic research (CASPER)California, USA

Andreas Fuhrmanek From single atom to many atoms in a 18.10.2011CNRS- Institut d’Optique microscopic optical dipole trapGraduate School, France

Bernard de Wit Elementary particles, strings and black holes 26.10.2011Utrecht UniversityThe Netherlands

Ravindra Venkatramani Moving charges through nucleic acid sequences: 28.10.2011Duke University making sense of mechanisms and rates inUSA dynamic media

Changbom Park Simulation of the SDSS survey region of the universe 09.11.2011Korea Institute for Advanced StudyRepublic of Korea

Yuri A Shchekinov Enrichment history of the Universe as 14.11.2011Southern Federal seen from GRB statisticsUniversity, Russia

Karthik Shankar Torsion induced modification to 15.11.2011Boston University, USA gravity can avert singularities

III151

Sudhir Vempati Higgs or No Higgs? 17.11.2011Indian Institute of ScienceBangalore

Rajesh R Isotropic-nematic-disorder transitions 29.11.2011Institute of Mathematical in a system of long rodsSciencesChennai

Sanjay Kumar Mechanical separation of short double 01.12.2011Banaras Hindu University stranded DNA: Effect of pulling geometryVaranasi

Subinay Dasgupta Quantum Ising Chain under periodic field: 08.12.2011University of Calcutta an exact solutionKolkata

Manjari Bagchi A study of observed luminosities of 09.12.2011West Virginia University millisecond pulsars in globular clustersUSA aiming a better understanding of this population

Fernando Barbero Black holes: combinatorics and the 09.12.2011Instituto de Estructura thermodynamic limitde la Materia, Spain

Sukanya Chakrabarti A new probe of the distribution of dark 12.12.2011Florida Atlantic University, USA matter in galaxies

Rafael D Sorkin Expressing entropy globally in terms of 13.12.2011Perimeter Institute field- correlationsCanada

Rajaram Nityananda Electromagnetic transmission through a 13.12.2011National Centre for parallel array of wiresRadio Astrophysics, Pune

Malay Bandyopadhyay Quantum transport at nanoscale: 15.12.2011University of Toronto two models for energy and charge transferCanada

Anantha Ramakrishna S Broadband extra-ordinary transmission 19.12.2011Indian Institute of of light through checkerboard plasmonic filmsTechnology, Kanpur

Yogesh Investigations on rotations and interactions 19.12.2011Bangalore University between microscopic objects by opticalBangalore tweezer based techniques

Yogendran KP Black holes and string theory 02.01.2012Indian Institute of ScienceEducation and Research, Mohali

III152

Kartik Sheth The starring role of bars in understanding 05.01.2012National Radio Astronomy galaxy evolution: Results from S4G,Observatory, USA COSMOS, DEEP2 and AEGIS

Nimesh A Patel Probing circumstellar chemistry with the 09.01.2012Harvard-Smithsonian submillimeter arrayCenter for Astrophysics, USA

Pinaki Chaudhuri Confined flow of soft jammed materials 10.01.2012Universitat Dusseldorf, Germany

Madhusudan Singh A few illuminating adventures with OLEDs 10.01.2012University of Texas, USA

Debashree Ghosh Understanding electron transfer processes 16.01.2012University of Southern in complex environments- Hybrid QM/EFP approachCalifornia, USA

Pavan Kumar Aluri Directional and power anisotropies in CMB 17.01.2012Indian Institute of TechnologyKanpur

Ashish V Orpe Dynamics of dense granular material 20.01.2012National Chemical Laboratory flowing within a fluidPune

Sharmila Kamat Hunting for WIMPs – the search for 23.01.2012Columbia University, USA dark matter in the universe

Ron Ekers 1. Lunar radio Cerenkov observations 24.01.2012Australia Telescope of UHE neutrinosNational Facility, Australia 2. Experiments in Radio Astronomy 16.01.2012

30.01.2012

Sharanya Sur Magnetic fields during the formation 31.01.2012Inter University Centre for of the first starsAstronomy & Astrophysics, Pune

Jane Roscoe Visibility - beyond the published article 31.01.2012Institute of Physics PublishingUnited Kingdom

John Philip Nanofluid- a wonderful model system 02.02.2012Indira Gandhi Centre for physicistsfor Atomic Research, Kalpakkam

Preeti Kharb Examining AGN unification and jet 06.02.2012Rochester Institute of Technology propagation in Radio-loud AGNUSA

Mark Bowick Facets of order 07.02.2012Syracuse University, USA

III153

Iyer BR LIGO-India Centre at RRI-Flagship Project 08.02.2012Raman Research InstituteBangalore

Swati Dandekar Water and a city 16.02.2012Independent Filmmaker

Miguel Campiglia Loop quantum cosmology in the 02.03.2012Pennsylvania State spinfoam paradigmUniversity, USA

Michael A Dopita The quantum vacuum, dark energy and 12.03.2012Australian National University dark matter Australia

Gaiti Hasan The calcium store(y) in neurons 15.03.2012National Centre forBiological Sciences, Bangalore

Subhadeep De Mixture of Bose-condensed rubidium 21.03.2012University of Maryland, USA and degenerate fermionic lithium

Soft Matter Chemistry Workshop

held at the Raman Research Institute between 9-11 November 2011

SpeakSpeakSpeakSpeakSpeakererererer TitleTitleTitleTitleTitle

Takashi Kato Development of nanostructured liquid crystals exhibiting photonic, ionic and electronic functions

Madhusudana NV An overview of liquid crystals with novel physical properties synthesized in theRaman Research Institute

Duncan Bruce New liquid-crystalline materials via heterocyclic compounds

Paul Kouwer Hierarchical organization in soft matter

Yo Shimizu Liquid crystals: dynamics systems towards novel semiconducting materials

Ehud Keinan Towards chemical capsids and cucurbituril-based chemical sensors

Rajiv Manohar Ferroelectric liquid crystals versus nano particles doped ferroelectricliquid crystals

Pratibha R Glassy nature for the dark conglomerate liquid crystalline phase

III154

Surajit Dhara Viscoelastic properties of some unconventional nematic liquid crystals

Manickam M Molecular materials: triphenylene-based discotic liquid crystals

Raj Kumar Gupta Surface pressure induced nanostructure formation in langmuir-blodgett filmsof tricycloquinazoline based mesogen

Ravindra Dhar Dielectric and electro-optical parameters of the mixtures of R andS enantiomers of an anti-ferroelectric liquid crystalline material

Chien LC Light embossed nano patterns for liquid crystal alignment

Suresh KA Novel discotic mesogen films at interfaces

Lakshminarayanan V Electrochemical studies in self-organized soft matter systems

Manjula Devi Effect of functionalized carbon nanotube on physical properties of aliquid crystal

Corrie Imrie Liquid crystal polymer electrolytes

Sri Singh Phase transitions in liquid crystals

Raghunathan VA Tuning DNA-amphiphile condensate architecture with strongly bindingcounterions

Sadashiva BK Liquid crystals of compounds composed of bent core molecules

Ramakrishnan S Janus hybramers: self-adapting amphiphilic hyper-branched polymers

Jayaraman N Fluorescent poly(ether imine)-based dendritic liquid crystals

Narayan KS Correlating electrical transport and morphology in bulk hetorstructurepolymer blends

Neelotpal Sen Sarma Development of thermistor device from the liquid crystalline polymers

Ohta K Development of discotic liquid crystals based on phthalocyanine-fullerene dyad

Satyendra Kumar What are cybotactic groups, swarms, clusters, correlated regions, andpretransitional fluctuations?

Vij JK Field induced switching in non-tilted polar orthogonal smectic phases inbent-core liquid crystals

Ruckmongathan TN A path to high performance liquid crystal displays

Bandyopadhyay R Rise of an intruder in a quasi 2D granular column is driven by granularconvection

Dabrowski R High birefringent nematic liquid crystals with positive, neutral and negativedielectric anisotropy

III155

Ashish Prajapati Symmetric and non-symmetric liquid crystal dimers:synthesis and mesomorphism

Tandel RC Effect of amide linkage on mesomorphism

Arun Roy The triclinic lamellar phases of the bent-core hockey stick shaped molecules

Thaker BT Calamatic metallomesogens: metal containing liquid crystals

Raina KK Optical enhancement investigations of polymer stabilized and guest – hostliquid crystals

Kula P Synthesis and properties of laterally fluoro-substituted4"-alkyl-[1,1’:4’,1"]terphenul-4-yl alkyl carbonates

Hari K Bisoyi Carbon-based liquid crystals

Vijayaraghavan D Magnetic susceptibility studies on micelles, vesicles and bicelles

Hatwalne Y The structure of twist grain boundary phases

3rd RRI School on Statistical Physics

held at the Raman Research Institute between March 26 - April 7, 2012

SpeakSpeakSpeakSpeakSpeakererererer TitleTitleTitleTitleTitle

Samuel J Brownian motion on curved surfacesRaman Research InstituteBangalore

Bhattacharjee SM Physics of polymersInstitute of PhysicsBhubaneshwar

Abhishek Dhar Introduction to methods of stochastic processes - IRaman Research InstituteBangalore

Sabhapandit S Introduction to methods of stochastic processes - IIRaman Research InstituteBangalore

Jarzynski C Nonequilibrium work relations and fluctuationsUniversity of Maryland, USA

III156

Ciliberto S Measuring nonequilibrium fluctuationsÉcole normale supérieureFrance

Gallavotti G Dynamical systems and fluctuation relationsUniversity of Rome, Italy

IV157

APPENDIX 4Visitors

Name and InstitutionName and InstitutionName and InstitutionName and InstitutionName and Institution Duration of staDuration of staDuration of staDuration of staDuration of stayyyyy

Nithyanandan T 6 April – 16 May 2011Columbia University, USA

Divya Sharma 10 – 12 April 2011Birla Institute of Technology & Science-Pilani, Hyderabad

Unnikrishnan CS 14 – 19 April 2011Tata Institute of Fundamental Research, Mumbai 23 – 24 June 2011

Umakanth Rapol 15 – 16 April 2011Indian Institute of Science Education and Research, Pune

Sudipta Sarkar 17 – 19 April 2011University of Maryland, USA

Amit Apte 19 April 2011Centre for Applicable Mathematics, Bangalore

Sandipan Sengupta 1 – 5 May 2011Institute of Mathematical Sciences, Chennai 29 – 30 November 2011

Sandeep Menon Perinchery 2 May 2011Macquarie University, Australia

IV158

Reetanjali Moharana 5 May – 5 June 2011Indian Institute of Technology, Mumbai 10 November – 31 December 2011

Arun KG 15 – 23 May 2011Chennai Mathematical Institute, Chennai 24 – 27 September 2011

21 – 26 February 2012

Sanjay Gupta 22 -27 May 2011S N Bose Centre for Basic Sciences, Kolkata

Brian Crosse 23 – 25 May 2011Curtin University, Western Australia

Harshal Bhadkamkar 23 – 26 May 2011Tata Institute of Fundamental Research, Mumbai

Edward Morgan 23 – 28 May 2011Massachusetts Institute of Technology, USA

Jinto Thomas 25 – 27 April 2011Institute for Plasma Research, Ahmedabad 2 – 26 May 2011

Ginson Joseph 17 – 18 May 2011St. Thomas College, Pala, Kerala

Ravi Chandra V 27 May 2011Israel Institute of Technology, Israel

Dana Anderson 20 – 28 May 2011University of Colorado, USA

Seshadri TR 29 May – 2 June 2011Delhi University, New Delhi 26 – 31 July 2011

1 – 8 October 20113 – 9 March 2011

Jayan Thomas 29 – 31 May 2011University of Arizona, USA

Gopal NO 31 May 2011National Dong Hwa University, Taiwan

Ashish Lele 31 May – 3 June 2011National Chemical laboratory, Pune

Mughda Gadgil 2 – 3 June 2011National Chemical Laboratory, Pune

Ghosh A 3 – 5 June 2011Indian Association for the Cultivation of Science, Kolkata

IV159

Anindya Banerjee 7 – 11 June 2011St. Xavier’s College, Pune

Ganesh V 10 – 16 June 2011Central Electrochemical Research Institute, Karaikudi 22 – 24 June 2011

Abhik Ghosh 12 – 13 June 2011Indian Institute of Technology, Kharagpur

Archan Dey 14 – 15 June 2011Eindhoven University of Technology, The Netherlands

Vikram Vyas 20 June – 13 July 2011St. Stephen’s College, Delhi

Priyam Das 30 June – 3 July 2011Indian Institute of Science Education and Research, Kolkata

Arvind Ayyer 1 July 2011University of California, USA

Marykutty James 1 July - 30 October 2011MG University, Kerala 10 - 31 March 2012

Chetana Jain 1 – 10 July 2011Delhi University, New Delhi

Surajit Dhara 5 – 6 July 2011University of Hyderabad, Hyderabad

Abhijit Sen 8 – 10 July 2011Institute for Plasma Research, Ahmedabad

Sujoy Kumar Modak 10 – 15 July 2011S N Bose National Centre for Basic Sciences, Kolkata

Sibhasish Gosh 10 – 14 July 2011The Institute of Mathematical Sciences, Chennai

Srinivas Sridhar 12 July 2011Northeastern University, USA

Krishnan N 14 – 15 July 2011Tata Institute of Fundamental Research, Mumbai 21 July 2011

Guillaume Faye 16 July – 13 August 2011Institut d’ Astrophysique de Paris, Paris

Rao DVGLN 28 July – 5 August 2011University of Massachusetts, USA 30 August 2011

IV160

Anders Kastberg 29 July - 31 August 2011Universite Nice Sophia Antipolis, France

Arundati Dasgupta 3 – 5 August 2011University of Lethbridge, Canada

Casey Tomlin 6 August – 7 October 2011Pennsylvania State University, USA

Govind Swarup 7 – 9 August 2011National Centre for Radio Astrophysics, Pune

Indranil Chattopadhyay 8 – 16 August 2011Aryabhatta Research Institute of Observational Sciences, Nainital

Srivathsan Vasudevan 11 August 2011National Technical University, Singapore

Onuttom Narayan 17 August 2011University of California, USA

Ruta Kale 20 – 31 August 2011Inter University Centre for Astronomy & Astrophysics, Pune

Robert Goeke 22 – 23 August 2011MIT Kavli Institute of Astrophysics & Space Research, USA 14 – 16 November 2011

11 – 14 March 2012

Paramita Barai 5 September – 2 October 2011International Centre for Theoretical Physics, Italy

Dutta Gupta 14 – 16 September 2011University of Hyderabad, Hyderabad

Avasthi DK 15 – 17 September 2011Inter University Accelerator Centre, New Delhi

Richard Dodson 24 September – 1 October 2011International Centre for Radio Astronomy Research, Australia

Subhasis Maity 19 – 20 September 2011Jadavpur University, Kolkata

Sourav Haldar 25 – 26 September 2011Centre for Cellular & Molecular Biology, Hyderabad

Andreas Fuhrmanek 5 – 26 October 2011CNRS-Institut d’Optique Graduate School, France

Hari Dass ND 13 – 16 October 2011Chennai Mathematical Institute, Chennai

IV161

Anya Choudhury 15 – 31 October 2011Tata Institute of Fundamental Research, Mumbai 18 – 23 February 2012

Dan Werthimer 17 – 19 October 2011University of California, USA

Ramesh K 17 – 20 October 2011Max-Planck Institute for Radio Astronomy, Germany

Jayaram N Chengalur 19 – 21 October 2011National Centre for Radio Astronomy, Pune

Yuri Schekinov 26 October – 19 November 2011Southern Federal University, Russia

Ravindra Venkatramani 26 – 29 October 2011Duke University, USA

Abhijit Ghosh 28 October – 30 November 2011Weizmann Institute of Science, Israel 3 – 7 January 2012

Aditya Dharmadhikari 31 October – 4 November 2011Tata Institute of Fundamental Research, Mumbai

Balakrishna K 7 – 9 November 2011Defence Research & Development Organisation, Mumbai

Jurek Malareki 10 November – 10 December 2011University of Western Australia, Australia

Karthik Shankar 15 – 16 November 2011Boston University, USA

Haripadmam PC 15 – 16 November 2011Indian Institute of Space Science and Technology, Trivandrum

Visweshwar Ram Marthi 16 – 19 November 2011National Centre for Radio Astrophysics, Pune

Gaurav Jagtap 21 – 30 November 2011Pune University, Pune

Poonam Mehta 21 November – 6 December 2011Delhi University, Delhi

Rajesh R 29 November 2011Institute of Mathematical Sciences, Chennai

Subinay Dasgupta 29 November – 10 December 2011Calcutta University, Kolkata

IV162

Sanjay Kumar 1 December 2011Banaras Hindu University, Varanasi

Manu M 1 – 15 December 2011Indian Institute of Technology, Kanpur

Karupuchamy 8 December 2011Kyushu Institute of Technology, Japan

Jack Douglas 8 December 2011National Institute of Standards and Technology, USA

Jesus Fernando Barbero Gonzalez 3 – 14 December 2011Instituto de Estructura de la Materia, Spain

Rafael Sorkin 7 December 2011 – 3 January 2012Syracuse University, USA

Manjari Bagchi 8 – 13 December 2011University of West Virginia, USA

Rajaram Nityananda 9 – 14 December 2011National Centre for Radio Astrophysics, Pune

Nalini H Issur 11 – 26 December 2011University of Mauritius, Mauritius

Sukanya Chakraborti 13 – 14 December 2011Florida Atlantic University, USA

Malay Bandyopadhyay 15 – 16 December 2011University of Toronto, Canada

Anirudh Krishna 15 – 30 December 2011Chennai Mathematical Institute, Chennai 26 – 29 January 2012

Ashish Asgekar 18 – 21 December 2011Netherlands Institute for Radio Astronomy, The Netherlands

Yogesh 19 December 2011Bangalore University, Bangalore

Ryuichi Fujita 20 December 2011Universitat des Baleares, Spain

Subbarao Kambhampati 20 – 24 December 2011Arizona State University, USA

Suresh Doravari R 23 December 2011California Institute of Technology, USA 12 – 29 January 2012

IV163

Himangshu Paul 25 – 26 December 2011Indian Institute of Science Education and Research, Kolkata

Supriyo Mitra 25 – 26 December 2011Indian Institute of Science Education and Research, Kolkata

Joanna M Rankin 27 December 2011 – 10 January 2012University of Vermont, USA

Abhijit Ghosh 3 – 30 January 2012Weizmann Institute of Science, Israel

Nimesh Patel 6 – 10 January 2012Harvard-Smithsonian Center for Astrophysics, USA

Ronald Ekers 8 – 30 January 2012Commonwealth Scientific and Industrial Research OrganisationAustralia

Pinaki Chaudhuri 9 January 2012Universitat Dusseldorf, Germany

Madhusudan Singh 10 January 2012University of Texas, USA

Pavan Kumar Aluri 11 January – 15 February 2012Indian Institute of Technology, Kharagpur

Sharanya SurInter 16 January – 5 February 2012Inter University Centre for Astronomy & Astrophysics, Pune

Debashree Ghosh 16 – 18 January 2012University of Southern California, USA

Tarun Souradeep 18 January 2012Inter University Centre for Astronomy & Astrophysics, Pune

Ashish V Orpe 20 – 21 January 2012National Chemical Laboratory, Pune

Sharmila Kamat 22 – 26 January 2012Columbia University, USA

Jane Roscoe 31 January 2012Institute of Physics Publishing, United Kingdom

Kavitha M K 31 January – 2 February 2012Indian Institute of Space Science and Technology, Trivandrum

John Philip 1 – 3 February 2012Indira Gandhi Centre for Atomic Research, Kalpakkam

IV164

Preeti Kharb 5 – 7 February 2012Rochester Institute of Technology, USA

Mark Bowick 7 February 2012Syracuse University, USA

Katherine Blundell 12 – 22 February 2012Oxford University, United Kingdom

Steve Lee 12 – 22 February 2012Oxford University, United Kingdom

Kumar M P 13 – 29 February 2012Manipal University, Manipal

Michael A Dopita 12 – 15 March 2012Australian National University, Australia

Subhadeep De 20 – 22 March 2012University of Maryland, USA

Anitha R Warrier 22 – 25 March 2012Indian Institute of Technology-Madras, Chennai

Vandna Gokhroo 23 February – 12 July 2012Tata Institute of Fundamental Research, Mumbai

V165

APPENDIX 5Journal Club

Discussed bDiscussed bDiscussed bDiscussed bDiscussed byyyyy PPPPPaper discussedaper discussedaper discussedaper discussedaper discussed DatDatDatDatDateeeee

Udaya Shankar N The application of compressive sampling to deconvolution 07.04.2011T.J. Cornwell and F.de HoogCommonwealth Scientific andIndustrial Research Organization (CSIRO), AustraliaAstronomy & Astrophysics, 528528528528528, (April 2011)

Arnab Pal On the orientational ordering of long rods on a lattice 07.04.2011A.Ghosh and D. Dhar, TIFREuro Physics Letters, 7878787878 20003 (2007)

Madhukar S Universality in the evolution of orientation columns in 28.04.2011the visual cortexMathias Kaschube et al.,Science, 330330330330330, 1113 (2010)

Abhishodh Prakash Hawking radiation and the boomerang behavior of massive 28.04.2011modes near a horizonG. Jannes et al.,Physical Rev. D, Apr 13, 2011

Shashikant Gupta Gravity modes as a way to distinguish between hydrogen 12.05.2011and helium-burning red giant starsTimothy R. Bedding et al.,Nature, 444447777711111, 608-611 (2011)

V166

Ramesh B Supermassive black holes do not correlate with dark matter halos 12.05.2011John Kormendy (University of Texas, USA)Ralf Bender (Universitats-Stemwarte, Germany)Nature, 469469469469469, 377-380 (2011)

Abhishek Dhar Experimental demonstration of information-to-energy 26.05.2011conversion and validation of the generalized Jarzynski equalityShoichi Toyabe et al.,Nature Physics, 66666, 988-992 (2010)

Pramod Pullarkat Measurement of the instantaneous velocity of a 26.05.2011Brownian particleTongcang Li et al.,Science, 328328328328328, 1673-1675 (2010)

Sanjib Sabhapandit Leindenfrost on a Ratchet 23.06.2011Guillaume Lagubeau et al.,Nature Physics, 77777, 395-398 (2011)

Andal Narayanan Observing the average trajectories of single photons 23.06.2011in a two-slit interferometerKocsis et al.,Science, 332332332332332 (6034), 1170-1173 (2011)

Vijayaraghavan D All-photonic multifunctional molecular logic device 14.07.2011Joakim Andreasson et al.,J.Am. Chem. Soc., In Press (2011)

Jyothi S Optical precursor of a single photon 14.07.2011Shengwang Du et al.,Phy. Rev. Lett., 111110606060606, 243602-243605 (2011)

Ranjini Bandyopadhyay Competing interactions in arrested states of colloidal clays 28.07.2011B.Ruzicka, L. Zulian, E. Zaccarelli, R. Angelini, M. Sztucki,A. Moussaid and G. RuoccoPhys. Rev. Lett., 111110404040404, 85701-85704 (2010)

Tridib Ray Millikelvin cooling of an optically trapped microsphere 28.07.2011in vacuumTongcang Li, Simon Kheifets and Mark G. RaizenNature Physics, 77777, 527–530 (2011)

Joseph Samuel Gentle Measurement 11.08.2011J.Volz et al.,Nature, 444447575757575, 210-213 (2011)

Kanhaiya Lal Pandey A new challenge for the LCDM model of the Universe 11.08.2011(Novel test of modified Newtonian dynamics with gas rich galaxies)Stacy S. McGaughPhys. Rev. Lett., 111110606060606, 121303-306 (2011)

V167

Arun Roy Glass transitions in quasi-two-dimensional suspensions of 25.08.2011colloidal ellipsoidsZhongyu Zheng, Feng Wang and Yilong HanPhys. Rev. Lett., 111110000077777, 65702-65705 (2011)

Nithyanandan It’s all done with mirrors: reflections on the familiar and 25.08.2011Thyagarajan yet deeply enigmatic nature of the looking glass

Vilayanur S Ramachandran and Diane Rogers-RamachandranScientific American Mind, 1111188888, 16-18 (2007)

Supurna Sinha Bose-Einstein condensation of photons in an optical microcavity 08.09.2011Jan Klaers et al.,Nature, 468468468468468, 545-548 (2010)

Solomon Ivan J Minimum output entropy of Gaussian Channel 08.09.2011S. Lloyd et al.,arXiv: 0906.20906.20906.20906.20906.2777776262626262

Anjan Roy Suppression of the coffee-ring effect by shape-dependent 22.09.2011capillary interactionsPeter J. yunker et al.,Nature, 44444777776, 6, 6, 6, 6, 308-311 (2011)

Nipanjana Patra A luminous quasar at redshift 7.085 22.09.2011Daniel J. Mortlock et. al.,Nature, 444447777744444, 616-619 (2011)

Shiv Sethi The Nobel Prize in Physics – 2011 20.10.2011Special Journal Club Session

Srinivasa R The Nobel Prize in Chemistry – 2011 03.11.2011Special Journal Club Session

Satyajit Rath The Nobel Prize in Medicine- 2011 24.11.2011National Institute of Special Journal Club SessionImmunology, New Delhi

Kumar N Time of first passage (ToFP) 12.01.2012

Debasish Saha Infinite penetration of a projectile into a granular medium 09.02.2012F.Paecheco-Va’zquez et al.,Phys. Rev. Lett., 111110606060606, 218001-218004 (2011)

Rajib Basak Thermal jamming of a colloidal glass 09.02.2012Praveen Agarwal et al.,Phys. Rev. Lett., 111110000077777, 268302-268306 (2011)

Prabu T Detection of pulsed gamma rays above 100 GeV from 23.02.2012the crab pulsar (The Veritas collaboration)E.Aliu et al.,Science, 334334334334334, 69-72 (2011)

V168

Sandipan Sengupta The geometry of sound rays in a wind 23.02.2012G.W. Gibbons, C.M. WarnickContemporary Physics, 5252525252, 197-209 (2011)

Biswajit Paul Two populations of X-ray pulsars produced by two 22.03.2012types of SupernovaeChristian Knigge et al.,Nature, 444447979797979, 372-375 (2011)

Shiv K. Sethi Generation of scaled protogalactic seed magnetic fields 22.03.2012in laser-produced shock wavesGregori et al.,Nature, 404040404011111, 480-483 (2012)

R a m a nR e s e a r c hI n s t i t u t eB a n g a l o r e

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