Lev Pontryagin
Lev Semenovich Pontryagin (Russian Лев Семёнович Понтрягин; * 21 Augustjul / 3 September 1908greg in Moscow, .. † 3 May 1988 ) was a Russian mathematician. Pontryagin was one of the most influential mathematicians in Moscow in Soviet times and founder of its own mathematician school.
He lost his eyesight at a gas stove explosion at the age of 14 years. Thanks to his mother Tatiana Andrejewna who read him mathematical books, he was a mathematician, despite his blindness. In many areas of mathematics, particularly with respect to geometric aspects of topology, he made important discoveries.
Pontryagin ended in 1929 graduated from the Moscow State University and a Ph.D. ( Doctor of Russian equivalent, habilitation ) in 1935 Pavel Alexandrov. In the same year he became a professor. From 1934 he was at the Mathematical Institute of the Soviet Academy of Sciences ( Steklov Institute), where he led his own Department of Topology and Functional Analysis from 1935.
When he was still a student, he achieved important results on the duality of homology groups in algebraic topology. He put in the 1930 headstones for an abstract theory of Fourier transformation by developing a theory of characters for commutative topological groups ( Pontryagin duality ). At the same time he solved Hilbert's fifth problem with it, which are dealing with the question whether locally Euclidean manifolds groups ( Lie groups ), for the Abelian ( commutative ) case (1934 ). In 1938 he published his classic book on topological groups.
In topology, he posed the problem of cocycles theory. This led to the introduction in 1940 of characteristic classes in the topology, which are now called Pontryagin classes. The Pontryagin - Thom construction forms one of the foundations of Kobordismentheorie. According to him also the Pontrjaginraum has been designated a special case of the Krein space.
Later he worked in the optimization theory. The Pontrjaginsche maximum principle, sometimes called minimum principle was formulated as a theory of Pontryagin and is still fundamental to the modern theory of optimal control. Proved it was the mid-1950s by Pontryagin and his students Vladimir Boltjanski, Revaz Gamqrelidse. Earlier versions are independently chosen by Magnus Hestenes (1950) and Rufus Isaacs and Constantin Caratheodory (1935 ).
In the 70s and 80s Pontryagin played an important role in Soviet science policy. He represented his country in the International Mathematical Union, was chief of the Editorial Board, which decided on the appearance of all books and editor of the major magazine " Matematitscheski sbornik ". He was then accused of anti-Semitic behavior, as occurred in a fierce debate in the 1970s with Nathan Jacobson, who was together with Pontryagin then Vice President of the IMU and improved travel opportunities of Jewish scientists from the Soviet Union. Pontryagin defended himself against it in an article in Science in 1979. Der Spiegel described him in 1979 as "Main [ of ] small, but [ ... ] influential clique of officials who have brought back racism in the Soviet research policy " and reported 've Pontryagin in private circle boasted " Matematitscheski sbornik " is now " free of Jews ". ( "In the past always came about one- third of the approximately one hundred posts, published the journal annually by Jewish scholars., 1975, when Pontryagin took over the management, their number dropped to twelve in 1976 to eight. In the first volume of the vintage 1977 appeared four Article by Jewish authors, in the second volume, it was only one, in the third volume no more. " ) He also played as many other famous Russian mathematician who was then moving up generation a role in the Luzin affair.
In 1970 he gave a plenary lecture at the ICM in Nice ( Les Jeux Differentiels Line Aires, Linear differential games) and also in 1958 in Edinburgh ( Optimum regulation processes). In 1962 he was invited speaker at the International Congress of Mathematicians in Stockholm ( A statistical problem- in the theory of optimal control). In 1939 he became a corresponding and in 1959 a full member of the Russian Academy of Sciences. In 1941 he was one of the first recipient of the Stalin Prize.