Person: Cam, Lucien Marie Le
Lucien Le Cam was a French mathematician and statistician who moved to America and produced important resuls in asymptotic theory.
Mathematical Profile (Excerpt):
- Neither of his parents had more than a very basic elementary education but they were hard working people.
- They were born in a poor part of Brittany and had to leave elementary school at ten or eleven because they had to work, but they were fine strong intelligent people.
- That is someone who leases a farm owned by someone else.
- After mass there was a one-hour study period, then breakfast, then a fifteen-minute break to use the outside toilets.
- Despite the generous act by the priests in funding Le Cam's education, it was disrupted by the war.
- Le Cam's favourite subject at the high school had been chemistry and he took chemistry books with him to the seminary.
- However, he was told that the only book he could bring in was the bible and anything else required special permission.
- The lycée in Clermont-Ferrand offered him a free noon meal each day but had no accommodation left.
- He rented a room nearby and attended the lycée taking the two-year course to prepare for the competitive examinations for the École Normale and the École Polytechnique.
- sixteen hours of lectures on mathematics, seven on physics, six on chemistry, etc., per week.
- However, that still left me a bit of leeway to see a few things at the university.
- He attended some university lectures and one day he went into a bookshop on his way there and bought a copy of Bourbaki's Éléments de Mathématique Ⓣ(Elements of mathematics).
- A group of fifteen people, including one of my favourite cousins, took over the military camp at La Courtine.
- The French military, who had been invisible since 1940, came out of the woodwork and tried to teach us to march in step and the like.
- Le Cam was still trying to get into university; the École Polytechnique was his first choice with the École Normale Supérieure as second choice.
- His attempts to sit the entrance examinations for the École Polytechnique failed since he was unable to get all the necessary documents to prove that he was racially French back to his grandparents (the German occupiers had introduced mechanisms to bar those with a Jewish grandparent).
- In December 1944 he took the examinations for the École Normale (fortunately, he did not need his parents and grandparents birth certificates for this).
- He passed the written paper but failed the oral examination.
- Rather than wait to try again in the following June, Le Cam began to take courses at the University of Paris.
- He asked Maurice Fréchet if he could take the examinations in probability despite not having attended the course but Fréchet said he would fail a student who had not attended lectures.
- He made the same request of George Darmois for the statistics course and was told that he could try the examination if he could find a set of notes from which to learn the material.
- Asking Darmois for advice on getting a job, Le Cam was advised that Électricité de France were looking for statisticians.
- He was appointed and, together with several other statisticians at the organisation, read statistics journals and attended statistics lectures at the university.
- He published his first paper Un instrument d'étude des fonctions alétoires: la fonctionnelle caractéristique Ⓣ(An tool for the study of random functions: the characteristic functional) in 1947 and, in the following year, the paper Sur certains classes de fonctions aléatoires Ⓣ(On some classes of random functions) which was joint work with Jean Bass.
- A turning point came in his career in 1950 when, through attending Darmois' seminar, he met Jerzy Neyman who invited him to spend a year at the University of California at Berkeley.
- During the year 1950-51 that he spent in Berkeley as a visiting lecturer, Neyman said that provided he take a Ph.D. he could remain at Berkeley.
- Before working on his thesis, however, he had to take the Ph.D. Qualifying Examination and was given the task of presenting fixed point theorems in a one-hour lecture.
- He spent too long presenting the background material in algebraic topology and never reached the fixed point theorems - he was failed.
- He was allowed to retake the examination a few months later and this time gave an excellent lecture presenting a clever proof of his own.
- However, one of the examiners thought (incorrectly) that the proof was wrong and Le Cam was given a bare pass.
- After the award of his doctorate, Le Cam was appointed as an Instructor in Mathematics and Junior Research Statistician at the University of California, Berkeley.
- In 1955 his position became an Assistant Professor in the Department of Statistics when the Department was founded.
- He achieved tenure at Berkeley when he was promoted to Associate Professor in 1958 and, two years later, became a full Professor.
- Let us now look at some of the books that Le Cam has published, all in the area of modern asymptotic theory of statistical inference of which he is one of the founders.
- The understanding of these seminar notes is enhanced by the author's inclusion of remarks, examples, and description of relations among various peoples' work.
- One of the main principles of the present book is to organize the large field of asymptotic statistical theory around a few essential ideas and elements.
- As the title indicates, this is done within the framework of Wald's decision theory.
- The exposition of the whole subject is such that anyone who wants to enter it needs to read only this book.
- Everything has been developed in detail, advanced techniques are fully explained, and results from classical analysis that are used in the text are collected in an extensive appendix.
- Some basic concepts (1990) producing a second edition increased in length by over 50% completed in 2000 shortly before his death.
- Although Le Cam made deep highly mathematical contributions to statistics, we should not give the impression that all his work was of this type.
- He made many contributions to the solution of practical problems such as studying stochastic models for rainfall, for the effects of radiation on living cells, sodium channel modelling and for cancer metastasis.
- Le Cam's extraordinary knowledge of cancer quickly gained the respect of the attending physicians and some of the people at the Mayo Clinic.
- He never lectured from notes.
- If his lectures were an overview, outside the classes he was extremely generous with his time and ideas.
- Le cam retired in 1991 and was made Professor Emeritus.
- This made surprisingly little difference to his daily routine and he continued to operate his "open door" policy in the Department.
- Le Cam was honoured for his many contributions in several different ways.
- He was President of the Institute of Mathematical Statistics in 1973, elected to American Academy of Arts and Sciences in 1976, elected a Fellow of the American Association for the Advancement of Science in 1977, made a member of the New York Academy of Sciences in 1982, and awarded an Honorary Degree by the Université Libre de Bruxelles in Brussel in 1997.
Born 18 November 1924, Croze, Creuse, France. Died 25 April 2000, Berkeley, California, USA.
View full biography at MacTutor
Adapted from other CC BY-SA 4.0 Sources:
- O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive