Charles Pisot

Charles Pisot ( born March 2, 1910 in Obernai; † 7 March 1984, Paris) was a French number theorist.

Life

Pisot studied from 1929 at the École supérieure normal in Paris ( completion in 1932, where he cut in the competition for the Agrégation as Best ) and his PhD in 1938 with Arnaud Denjoy (La répartition modulo 1 et les nombres algébriques ). He then worked as a secondary school teacher. In the 1940s, he sought a professorship in occupied Germany from Alsace (he was born in Alsace ), but failed because of his French citizenship (despite intercessions of Wilhelm Süss) .. From 1946, he was Maître de conférences and from 1948 professor at the University of Bordeaux. In 1955 he received a professorship at the Faculté des Sciences in Paris, where he led a company founded by Albert Châtelet number theory and algebra seminar with Paul Dubreil. This was followed in 1960 the seminar DPP ( Delange - Pisot -Poitou ) with Hubert Delange ( 1913-2003 ) and Georges Poitou ( 1926-1989 ). In 1979 he retired. In addition to his professorship he was Maître de conférences at the École polytechnique.

He was a member of Bourbaki. In 1966 he received the grand prize of the city of Paris from the French Academy of Sciences.

He had numerous pupils. His doctoral include Yvette Amice, Jean -Marc Deshouillers.

Work

Pisot worked on number theory, which was then largely neglected in France and the Pisot revived there with his seminar. In his thesis he introduced the eponymous Pisot numbers which he later extensively examined ( he never called it Pisot numbers, usually they were called figures of the class S), as well as the related, in the 1940's by Raphael Salem ( of the connection with harmonic analysis discovered ) introduced Salem numbers ( called numbers of the class T).

Pisots textbook Mathematiques Generales with Marc Zamansky was widespread in the 1960s and 1970s in France.