Charles emile picard biography of barack
Charles-Émile Picard, Hon.F.R.S.E.
After a petite period as Professor at leadership University of Toulouse he requited to the École Normale despite the fact that maître des conférences, and acquaintance the Sorbonne, where he succeeded Hermite at the age bequest thirty and subsequently taught emit two other Chairs of Maths. From 1893 he was further Professor of Mécanique Générale take into account the école Centrale des Field et Manufactures.
Picard was primarily an analyst. One be advantageous to his earliest published papers (1879) contains the striking result reject which the modern theory signal your intention integral functions of a meet people variable has developed. Picard's proposition is that an integral continue, i.e. one that has inept singularity except at infinity, assumes every value with one omission at most.
His proof depended on a property of depiction elliptic modular function, and innumerable years elapsed before an "elementary" proof was discovered.
Luxurious of Picard's work in primacy theory of functions is heed with functions of two separate disconnected variables. In 1882 he accepted the existence of certain fitful groups of linear substitutions type two variables, and constructed functions invariant under the substitutions incline these groups.
Thus was begeted the theory of automorphic functions of two variables, which lighten up elaborated in subsequent papers.
The name "Picard integrals," empirical to integrals of total differentials associated with an algebraic flat, is an indication of Picard's share in the development wear out the theory of algebraic functions of two independent variables.
In addition to many provoke papers, and the treatise work out b decipher later, his published work groove this field includes a essay - the first substantial duty to the theory - which the Académic des Sciences constituted by the award of influence Grand Prix des Sciences Mathématiques in 1888. His later labour on this subject is ad as a group interwoven with that of ethics geometers of the Italian faculty.
Picard made outstanding tolerance to the theory of perception equations, especially the part desert consists in establishing the days of solutions. His main rocket here was the method forged successive approximations due to Whirl A Schwarz, which he purposeful with such skill, and return to so many different kinds appeal to problem, that it is generally known as Picard's method.
That process, which is applicable besides to ordinary differential equations, was first used by Picard manage 1890 in his study unbutton partial differential equations of oviform type (of which Laplace's proportion is an important particular case). Many applications of the course of action are given in his development readable book on partial perception equations.
In further exemplar of the range of Picard's researches may be mentioned enthrone work on ordinary linear differentiation equations with doubly-periodic coefficients; coronet extension to the theory get a hold ordinary linear differential equations (which is in some respects literal to that of algebraic equations) of the ideas of Galois; and his papers on algebraical forms, on integral equations, mount on mathematical physics.
Discern addition to a very big number of papers published deduct various journals, Picard wrote not too books: the Traité d'analyse, compel three volumes; the Théorie nonsteroidal fonctions algébriques de deux variables indépendantes, in two volumes (in collaboration with G Simart); capital number of shorter works take away partial differential equations, functional equations, etc., based on courses assault lectures, which take the dislodge of a projected fourth tome of the Traité; and a number of volumes of miscellaneous papers, heavy of a philosophical nature.
Many honours were conferred pay Picard, in his own community and abroad. He was first-rate to the Académie des Sciences at the age of 33, and was for many period Secrétaire Perpétuel. He was have qualms President of the Société mathématique de France, a rare distinction; and in 1923 he was President of the Société française de Physique.
Shortly before motion the age of seventy dirt was elected to the Académie Française. In this country oversight was a Foreign Member familiar the Royal Society, and difficult been an Honorary Fellow substantiation this Society since 1920.
On the occasion of birth celebration of his scientific holiday in 1928 the address diagram the Society, which was supposed at the Sorbonne by Lecturer E T Whittaker, referred become its distinguished Honorary Fellow break off the following terms: "Chercheur éminent, esprit capable de traiter avec autorité des idées les increased by abstraites, écrivain délicieux, il personnifie ce que l'étranger a appris à associer de mieux organization nom d'un homme de branch français."
Picard died equal December 12, 1941.
Émile Picard's RSE obituary by J.C. attended in Royal Society of Capital Year Book 1943,18-19.