ABSTRACT
Poincarés first great achievement came in pure mathematics, where he generalized the idea of functional periodicity in his famous theory of automorphic functions, which he called Fuchsian functions in honor of the German mathematician I. L. Fuchs (1833-1902). In the field of celestial mechanics he made substantial contributions to the theory of orbits, in particular as related to the three-body problem. He de veloped important new mathematical tools during these investiga tions. The results of his research on new mathematical methods in astronomy were systematized in the work Les M éthodes nouvelles de la m écanique céleste, which appeared in three volumes between 1892 and 1899. Poincaré also made valuable contributions to the theory of the figures of equilibrium of rotating fluid masses, but his most important contribution to mathematical physics was his paper on the dynamics of the electron (1906) in which, independently of Einstein, he derived many of the results of the special theory of relativity.
