Sergei Natanovich Bernstein
Sergei Natanowitsch Bernstein (Russian: Сергей Натанович Бернштейн, scientific transliteration Sergei Natanovič Bernštejn; * 22 Februarjul / March 5 1880greg in Odessa, .. † October 26, 1968 in Moscow) was a Russian mathematician.
Life
Bernstein studied ( Sorbonne, College of Electrical Engineering École Supérieure d' Electricité ) and Göttingen ( 1902/ 03) in Paris and in 1904 at the Sorbonne and again in 1913 ( candidate status ) Ph.D. in Russia at the University of Kharkiv, since there foreign doctoral degrees were not admitted. 1907 to 1932 he was a professor in Kharkiv. In 1933 he became a professor at the University and at the Polytechnic Institute in Leningrad and from 1943 in Moscow, where he died in 1968.
Work
In his first doctoral thesis Bernstein solved Hilbert's 19th problem on the solution of elliptic partial differential equations. In his second doctoral thesis, he devoted himself to Hilbert's 20th problem: he proved the existence of analytical solutions of the Dirichlet problem for a large class of nonlinear elliptic partial differential equations.
Amber is known primarily for his work on approximation theory, a field in which Russia already worked Chebyshev. For constructive proof of the theorem of Weierstrass, he led the 1911 Bernstein polynomials named after him. At the International Congress of Mathematicians in Cambridge in 1912, he also formulated a conjecture, which have worsened the set of Weierstrass and was proved by Chaim Müntz and Otto Szász. Bernstein was also involved in probability theory. Already in 1917 he attempted an axiomatization of probability theory ( which eventually Andrei Kolmogorov generally convincingly developed ). He presented the investigations into the central limit theorem, the law of large numbers, stochastic processes and applications, eg in genetics.
In 1932 he gave a plenary lecture at the International Congress of Mathematicians in Zurich ( Sur les liaisons entre quantites aléatoires ).
In Moscow Bernstein published the collected works of Chebyshev.