Moshé à la Suedoise

Memories of Moshé Flato, 1937 - 1998.

Håkan Snellman
Teoretisk fysik

In the fall of 1968, as I came home with my family from two years in Copenhagen, I first heard about Moshé Flato. One of the young researchers at our department told of a French-Israeli mathematician who had visited Stockholm, who wanted to regularize quantum field theory with gravitation and who was a master of symmetries. It didn't give me any clear idea, but I was soon to find out better.

When Moshé came to Stockholm next time I took my chances. At the Opera they gave Busoni's Faust in an ``mise en scene'' with laser beams as the demons! Hearing that Moshé was interested in music, I invited him in the hope that this ultramodern set up would interest him, but I think in the end that Moshé liked Gounod's version of Faust better; that type of music was more in his taste. We nevertheless became good friends, and he slowly and patiently introduced me into his world of mathematical physics.

In May 1970 I visited Moshé in Paris during one month, together with my colleague Göran Lindblad. In coffee-shops and in the crammed apartment at Rue Rollin we had intense discussions on all aspects of physics and mathematics, not to mention innumerable other topics as well that Moshé was able to be updated on due to his vast interests and formidable memory.

Moshé was a person who would always try to follow your thinking far out into deep waters, as long as he felt some new thought was worthwhile to explore. He did not kill an idea just because it was not well behaved and immature. This supportive and genuinely helpful attitude of Moshé was immensely important to a young scientist like me and I know it has been to many others.

At that time I was interested in certain aspects of current algebras, in particular whether the charge operators could be shown to be observables. I had found some reasonable conditions under which this was possible and Moshé immediately was interested, encouraging and helpful. This was later to lead to further joint work on the integrability of Lie-algebra representations.

In the fall of 1970 Moshé came, with his friends and collaborators Daniel Sternheimer and Jacques Simon, to the Royal Institute of Technology (KTH) in Stockholm for one year as Nordita guest professor. This was to change the course of theoretical physics, and even the lives, for several of us young students. Not only so in a gastronomical way, with unforgettable lunches and dinners, but also from the French-Swedish collaborative point of view, greatly aided by Moshé's friend Mr G. Karpmann, French ``attaché scientific'' in Stockholm at that time. This started as a series of conferences which Moshé initiated in 1967 with our group at KTH and with his friend Gunnar Källén; they were given Källén's name since Källén died a few months before the first event. Later this was to develop into a French-Polish-Swedish collaboration network with late Ryszard Raçzka of Warzaw at the Polish side.

At KTH Moshé gave 5 lectures on ``Quantum mechanics for pedestrians''. They came about from a bet. The audience of students in a lecture at KTH was said to decline almost exponentially with the number of lectures. Moshé claimed that he would give five lectures on quantum mechanics to students and keep more than half of the audience to the last lecture. He won the bet.

The strong impression and inspiration Moshé had on my scientific work extended on the personal side to a warm and bright, lifelong friendship also with my family. By the end of the year he suggested I should go with him to Paris and also helped me to obtain funding within the bilateral French-Swedish scientific exchange program. In the fall of 1971 my family and me finally were able to install ourselves in Boulogne-Billancourt for one year. This was to be an unusually fruitful year for me, and my own research was to follow ideas developed in collaboration with Moshé during these years well into the late 70's. One of my students, Göran Tengstrand, also made part of his thesis along these lines.

Throughout the years to follow I was privileged to be able to meet and discuss with Moshé many times, and each time was like an injection of intellectual and emotional vitamines in the blood-circulation. When I look back on these times my first reaction is gratitude. Gratitude that providence allowed my life-line to cross with his, and come into contact with his warm personality and bright intellect.

Moshé's warm radiation and interest in people gave him also a natural ability to become friends with people of all ages and walks of life, not least children, and children are often very sensitive to how elderly people relate to them. Our children became very friendly with him and they always felt his genuine interest in their whereabouts. Later in life they visited him and Daniel in Paris several times and tried always to be around whenever they heard that Moshé was to visit Sweden. In late October 1998, when Moshé and Daniel visited the Mittag-Leffler Institute in Stockholm, we could all come together again in our home. Little did we then suspect that this was to be the last time.

A truly great and generous soul has passed on to other orbits of existence, but his light is still warming all of us who were given the privilege to know him.

Håkan Snellman, Stockholm, March 1999.