Abraham Plessner

Ezekiel Abraham Plessner ( born February 13, 1900 in Łódź, † April 18, 1961 in Moscow) was a Soviet mathematician who worked on Analysis.

Life and work

Plessner was born in what was then Russian Łódź as the son of a merchant and factory owner. He attended secondary school ( where the language of instruction in the course of political development was alternately Russian, German and Polish last ). After graduation in 1918, he studied from 1919 at the University of Giessen ( Ludwig Schlesinger and Friedrich Engel ), the University of Göttingen ( with Richard Courant, Edmund Landau, Emmy Noether ) and at the Humboldt University of Berlin (with Richard von Mises, Ludwig Bieberbach, Isay Schur ). In 1923 he earned his doctorate under Schlesinger in Giessen ( On the theory of conjugate trigonometric series ). He also assisted Schlesinger in his book on Fourier series and Lebesgueintegrale. 1925 to 1928 he was assistant Kurt Hensel in Marburg, he assisted in the publication of the works of Leopold Kronecker. He then returned Wizard of Schlesinger in Giessen.

Here he qualified, but despite the efforts of angels and Schlesinger not be a lecturer, as he still had Russian citizenship. Plessner went via Berlin to Moscow, where he taught at the Moscow State University and the Steklov Institute of Mathematics of the Soviet Academy of Sciences from 1932. In 1935 he completed his habilitation at the University of Moscow (Russian doctorate ), and in 1938 he became a professor. He was a key member of the Soviet school of functional analysts. After the war, he lost to the influence of Vinogradov back in 1949 his post at the University and the Academy. He had health problems that prevented him also used to improve in his small pension by teaching.

Plessner dealt first with Fourier series and function theory, where the set of Plessner is named on the boundary behavior of meromorphic functions in the unit circle disc after him. In Moscow he studied ( under the influence of the dominant in Moscow Lusin - school and the book Theory of the surgeon lineaire of Stefan Banach ) with functional analysis and spectral theory specifically. His book spectral theory of linear operators ( in Russian), on which he worked since 1948, appeared posthumously in 1965.

Among his students in Moscow belonged Israel Gelfand.