lecturing in Collège

A few weeks ago I gave a seminar on ABC (and its asymptotics) in the beautiful amphitheatre Marguerite de Navarre (a writer, a thinker, and a protector of writers like Rabelais and of reformist catholics, as well as th sister of the Collège founder, François I) of Collège de France, as complement of the lecture of that week by Stéphane Mallat, who is teaching this year on Learning and random sampling. In this lecture, Stéphane introduced Metropolis-Hastings as one can guess from the blackboards above! The amphitheatre was quite full since master students from several Parisian universities are following the course, along the “general public” since the first principle of the courses delivered at Collège de France is that they are open to everyone, free of charge and without preliminary registration! (As a countermeasure to the monopoly of the university of Paris, following the earlier example of the 1518 trilingual college of Louvain). Here are the slides I partly covered in the lecture.

Francis Comets (1956-2022)

Francis Comets, with whom I taught at Polytechnique in the early 2000’s, and whom I highly respected, has most sadly died on June 6. Here is a eulogy written by Patrick Cattiaux, Giambattista Giacomin, and Lorenzo Zambotti, on the site of the Société Mathématique de France (translated from the French).

Francis was a rare person. Combining both a form of conformism and a surprising originality, he marked all those who knew him: colleagues, relatives, friends. A former student of the École Normale Supérieure de Saint Cloud, in 1987 he defended a Thèse d’État at the University of Paris Sud on problems of large deviations in connection with models of statistical physics. Very quickly he demonstrated his appetite for various fields combining probability, statistics and physics. Just check out his list of publications. Francis will remain as one of the pioneers in France in the study of models in random environments for which his contributions are internationally recognized, symbolized by the Ito prize from the Bernoulli Society received in 2015. Beyond a leading scientific activity, Francis has been for forty years a major player in the structuring of mathematics in France. First assistant at the University of Paris X, then Professor at Marne la Vallée and finally at Paris 7 (which over time became Paris Diderot and now Université Paris Cité), he has, during his academic career, spared no effort in serving the community. Director of the Laboratory of Probability and Random Models, co-founder of the Fondation Sciences Mathématiques de Paris, part-time professor at the École Polytechnique, he has devoted a very large part of his time to the French mathematical community. His students and his colleagues have found in Francis listening, empathy, competence and that hint of surprise that leads to curiosity. His friends and loved ones will express the deep and personal feelings that bound them to a rare being, as mentioned above. The French mathematical community joins in the grief of his family and friends at such a painful time.

Statistical Demography by Adrian Raftery [lectures]

ring of fire [jatp]

While leisurely biking in Paris the previous (grey) weekend, my wife and I stopped by the entrance to the Jardin des Plantes, in front of a (grey) renovated building of l’Institut de physique du globe, where we both attended (maths) lectures in the 1980’s. I had noticed the renovation years ago and in particular the red neon fractured line going over the faces of the building, but never considered it had a specific meaning.In fact, the apparent random walk has nothing random as it reproduces the Ring of Fire, a Fuller projection of the continuum of volcanoes that ring the Pacific Ocean. (This sculpture was created by Angela Detanico et Rafael Lain.)

Jean-Paul Benzécri (1932-2019)

I learned last weekend that Jean-Paul Benzécri had died earlier in the week. He was a leading and charismatic figure of the French renewal in data analysis (or analyse des données) that used mostly algebraic tools to analyse large datasets, while staying as far as possible from the strong abstraction of French statistics at that time. While I did not know him on a personal basis, I remember from my lecturer years there that he used to come to Institut de Statistique de l’Université de Paris (ISUP), Université Pierre et Marie Curie, once a week and meet with a large group of younger statisticians, students and junior faculty, and then talk to them for long hours while walking back and forth along the corridor in Jussieu. Showing extreme dedication from the group as this windowless corridor was particularly ghastly! (I also remember less fondly hours spent over piles and piles of SAS printout trying to make sense of multiple graphs of projections produced by these algebraic methods and feeling there were too many degrees of freedom for them to feel rigorous enough.)