Istituti di fisica

Rockefeller Chapel in Chicago where graduates got their diplomas

Remembrances of Luigi in Chicagoby Paul Cull, Oregon State University, USALuigi Ricciardi came to Chicago in 1969 as Assistant Professor of Mathematical Biology. At that time, the Committee on Mathematical Biology was being expanded and was expected to morph into the Department of Theoretical Biology.Luigi was among a group of young new assistant professors who went on to distinguished careers. In this group, there were such names as Art Winfree, Stuart Kauffman, and Montgomery Slatkin. They joined a group that included such established professors as Jack Cowan, Dick Levins, and Richard Lewontin, as well as recent recruits who were already well-known in other fields, such as Stuart Rice and Morrel Cohen. There was also a distinguished roster of visitors, including Warren McCulloch, Michael Arbib, E. O. Wilson, Rene Thom, and Eduardo Caianiello.

At that time, neural nets were a hot topic. McCulloch, who had invented neural nets 25 years earlier, was still active and he had a number of students working in that area. Stu Kauffman had recently shown that related Boolean models could also be used to describe genetic systems. Since Luigi had worked on neural nets with Caianiello and DeLuca, it seemed natural that he should supervise my thesis on neural nets. My thesis showed that techniques from linear algebra could be used to study neural nets if they were considered as polynomials over finite fields rather than as linear threshold devices. I successfully defended my thesis in June 1970 with Luigi as my major professor and Prof. Caianiello as a member of my committee.

The first year in Chicago was hard on Luigi. The weather was terrible. I don't think that he had ever faced weather as cold and intemperate as that of the Windy City. When Renato Capocelli came to visit, he was dressed in a beautiful Italian suit and leather shoes with pointed toes. It snowed heavily and the Chicago slush ruined his bella figura.

I remember that Luigi was very devoted to his work. He would arrive at the office several hours before I ever made an appearance. Luigi lived in an apartment in faculty housing that was located across the Midway. The area just south of his building was considered too dangerous, and university students and faculty were warned not to venture there. The university had its own police department that patrolled constantly, but even they weren't safe. One morning one of the officers was found shot dead in his patrol car.

Tonia was just a baby. Luigi and Kimiko would push her in a stroller around campus when the weather permitted. Being a new parent restricted Luigi's social activities. Many of the grad students and faculty would gather at Jimmy's, the local pub, particularly on Friday nights. These drink-filled sessions were also filled with scientific gossip. Who was doing what? What was wrong with X's latest paper? How had Y made a fool out of X. Unfortunately, Luigi was too tied up to attend many of these sessions.As soon as the school year finished, Luigi and family fled back to the sunny climes of Naples. He did, of course, return to Chicago and worked there for about 6 years. During this period, he wrote the seminal book "Diffusion Processes and Related Topics in Biology".

On the whole, Chicago didn't agree with Luigi. He hated the weather. The university, faced with financial problems, eventually dissolved Mathematical Biology. So I think that when a professorship was proffered in Italy, Luigi jumped at the opportunity, even if it was in Turin. Eventually he was able to return home to the Mezzogiorno, to Salerno and Naples.

Maybe you can take the boy out of Italy, but you can't take Italy out of the boy.

Our Message to the Congress in Honor of Luigi Ricciardiby Paul Cull, Oregon State University, USA The sad news of the passing of Luigi Ricciardi flew quickly across the seas and borders to break our hearts on the west coast of America. For more than 40 years he was our friend and colleague and we loved him dearly. In addition to inspiring scientific inquiry around the world, he taught us never to leave home without a pepperoncino. Let this be our consolation: that we are better people for having known him. May his legacy live forever in the scientific collaborations that he established and in our mutual friendships.

Luigi with Henry Tuckwell and Hugh Wilson

I am very pleased that Laura has given me the opportunity to convey to you some of my thoughts and memories of Luigi.Luigi stands out in my mind as an unusually kind, tolerant, and generous man with a cheerful spirit which made it a pleasure to be around him. He got on very well with everybody. He was also an energetic, inspiring and talented mathematician.I knew him firstly at the University of Chicago in the early 1970's where I was a graduate student in Theoretical Biology and Luigi was a professor. At that time his good friend and colleague Renato Capocelli would often visit and I remember how devastated Luigi was when Renato died at an early age.The days in Chicago were filled with interesting people - especially post docs like Arthur Winfree, Hugh Wilson, Curtis Strobeck, Paul Cull and Leon Glass...to name a few. Many of these would stay friends with Luigi for the rest of his life, being invited many times to the biomathematics conferences that Luigi organized in Vietri and elsewhere.It is not an understatement to say that without Luigi I would not have ended up with a doctorate from the University of Chicago. I had gone there in 1969and my assigned supervisor, whom I will not name, and I did not have a good relationship. In part this was due to my being quite distracted from my studies, but on the other hand I found the long sequence of exams and the work proposed by the supervisor to not be very interesting. I was thenwithout an official supervisor so at this point it looked like my studies in Chicago would end.Finally I somehow scraped through the (double) qualifying exam and fortunately for me, Luigi stepped in around 1971 or 1972 to supervise me firstly with a Master's degree on diffusion processes. The whole subject of stochastic processes and stochastic differential equations especially with applications in biology I found very interesting. I also worked with discontinuous processes and only about 15 months after getting the Master's degree I had finished my PhD.

Message to the Congress in Honor of Luigi Ricciardiby Henry Tuckwell

I was lucky to get a job at the University of British Columbia in Vancouver and have since worked at some illustrious institutions such as UCLA, the Institute for Advanced Studies in Canberra, the University of Paris and now at the Max Planck Institute for Mathematics in the Sciences in Germany. None of this would have been possible without Luigi's rescuing me in 1972 for which I am deeply grateful.Just one example of Luigi's kindnesses, in addition to the pleasant meetings in Vietri.In 1987 Luigi organized a meeting In Capri. One of my best memories of this meeting was hearing his daughter give a piano recital in a lovely church, which inspired me to get back to playing and writing music myself!At the time of the meeting I was based in Melbourne but was a visiting professor in the Math dept at UCLA. After the conference, I had to fly from Naples to Rome to get a plane to Los Angeles. But, Al Italia went on strike so I couldn't make my connection. Luigi made the quick and generous decision to get me a taxi from Naples to Rome, which was a trip of 177 km. It cost a lot of money (about 400 US dollars at the time) and the trip was rather hair-raising as we passed about every car on the road but I did make it and was able to not miss any lectures back in LA!Luigi was a singular person. A few years ago he gave me a wonderful surprise by presenting me with copies of both theses I wrote when he was my supervisor in Chicago.It is a great pity that he had to die so young as there are too few people with his wonderful nature. I am very grateful that such a fine human being entered my life and played such a significant and positive role in my career. I miss him very much.

With regards and sympathy to all present.Henry Tuckwell October 11, 2011.

Chicago group: Henry Tuckwell, Luigi, Simon Levin (not Chicago), Hugh Wilson,

Leon Glass and Charlie Smith.

Message to the Congress in Honor of Luigi Ricciardiby Charles E. Smith

I have many fond memories of Luigi Ricciardi as a teacher, mentor, and colleague and as a dear friend.

Upon entering graduate school, I was impressed by the course on stochastic processes in biology by Prof. Ricciardi. He patiently lead us through a path among difficult topics while emphasizing the salient ideas and methods in a patient manner. Later when I was collecting the notes for the Luigi’s Lecture Notes in Biomathematics book I appreciated even more the skill and care in the path he had chosen to lead new graduate students.

These days we hear much about mentoring, Luigi’s mentoring skills were a model for us all. I think they were based in his genuine care for others. Henry Tuckwell and I were working on a paper for a Canadian biomath conference and I was hesitating about going as I had never given a paper at a meeting before. Luigi encouraged me to go, helped with slides and patiently tolerated my early nervous attempts at practice runs. He tried to bring out the best in all those he was in contact with and urged them to stretch beyond what they were comfortable with. He and Kimiko also encouraged the students in other ways. I also remember when he invited the graduate students to his house in the fall. I was thinking, wow this is the best dinner I have had in ages and then was informed that was only the first course.

He also had an uncanny ability to organize and run wonderful conferences with new ideas, ample opportunities to meet and interact with new colleagues as well as old friends and held in a timeless place of beauty. Having the full moon rising over Naples bay from the BIOCOMP banquet just at the time they were giving a cheer for Prof. Hida’s birthday must have taken incredible planning. If Luigi was in charge of something, then everything was impeccably organized as usual.He also introduced me to Japan and Japanese culture and Prof. Shunsuke Sato. Luigi-sama, doumo arigatou gozaimasu.Occasional by email or in person we would exchange haiku or other poems each had written. I had shared a longer poem Season of Roses that was my first one published in the literary magazine Magnapoets. Part of Prof.Ricciardi’s email response to that given below, I think well describes how many of us felt upon receiving the news of his death:Long stem roseslook beyond the horizonfeeling lostBut this meeting is to celebrate Luigi’s life, his vivaciousness was infectious and his generosity unparalleled. We sorely miss him, but by passing on his vivaciousness, generosity, mentoring skills to our students and colleagues we can honor him and his many accomplishments. Charlie Smith

Istituto di Scienze dell’Informazione

Torino 1993

SMB Newsletter vol 24 #3 (Sept 2011).

Salerno 19 febbraio 2010