Jean Chazy
Jean Chazy ( born August 15, 1882 in Villefranche -sur -Saône, † March 9, 1955 in Paris) was a French mathematician and astronomer.
Chazy was the son of an industrialist and studied at the École Normale Supérieure in Paris mathematics with the completion of Agrégation 1905. He was in 1910 a PhD ( differential equations du troisième ordre et d'ordre supérieur dont l' intégrale générale a ses critiques fixed points ). In 1911 he was Maître de conférences of Mechanics in Grenoble and then in Lille. In World War I he served in the artillery. After the war he was again professor at the Faculté des Sciences de Lille (later the University of Lille). At the same time he taught at the Institut industriel du Nord ( Ecole Centrale de Lille). Then he ( the examiner at the École polytechnique as well ) from 1923 Maître de conférences at the École centrale des arts et manufactures in Paris and from 1924 Professor of Mechanics and later for celestial mechanics at the Sorbonne. In 1953 he retired.
He dealt with celestial mechanics and especially the three-body problem and the perihelion of Mercury, which had a small discrepancy to the classical celestial mechanics calculation, which was explained by Albert Einstein by the General Theory of Relativity.
From 1909 he studied nonlinear differential equations, which are named after him, have connections to the soliton theory.
In 1937 he became a member of the Académie des Sciences ( Astronomy ). He was a member of the Romanian Academy of Sciences and member of the Royal Belgian Academy of Sciences. In 1934, he was President of the French Mathematical Society, after serving as its secretary. Since 1952, he was officially a member of the Bureau des Longitudes. He was commander of the Legion of Honour.
He was invited speaker at the International Congress of Mathematicians in 1924 in Toronto (On the arrival of a strange star in the solar system, French) and in 1928 in Bologna ( On the stability of the three- body problem by Poisson, French).
Writings
- La théorie de la relativité et la mécanique Céleste, Volume 1, 1928, Volume 2, 1930, Gauthier -Villars, Paris
- Cours de mécanique rationnelle, 2 volumes, Gauthier -Villars 1933, new editions 1941/42, 1948, 1952
- Mécanique Céleste: équations canoniques et variation of Constantes, Presses Universitaires de France, Coll. Euclide, Paris 1953