Lev Semyonovich Pontryagin (Russian: Лев Семёнович Понтрягин, also written PontriaginorPontrjagin, first name sometimes anglicized as Leon) (3 September 1908 – 3 May 1988) was a Sovietmathematician. Completely blind from the age of 14, he made major discoveries in a number of fields of mathematics, including algebraic topology, differential topology and optimal control.
He was born in Moscow and lost his eyesight completely due to an unsuccessful eye surgery after a primus stove explosion when he was 14. His mother Tatyana Andreyevna, who did not know mathematical symbols, read mathematical books and papers (notably those of Heinz Hopf, J. H. C. Whitehead, and Hassler Whitney) to him, and later worked as his secretary. His mother used alternative names for math symbols, such as "tails up" for the set-union symbol .[1]
Starting in 1952, he worked in optimal control theory. His maximum principle is fundamental to the modern theory of optimization. He also introduced the idea of a bang–bang principle, to describe situations where the applied control at each moment is either the maximum positive 'steer', or the maximum negative 'steer'.[citation needed]
Pontryagin authored several influential monographs as well as popular textbooks in mathematics.
Monument to Lev Pontryagin on wall of building on Leninsky AvenueinMoscow, where he lived from 1939 to 1988.
Pontryagin participated in a few notorious political campaigns in the Soviet Union. In 1930, he and several other young members of the Moscow Mathematical Society publicly denounced as counter-revolutionary the Society's head Dmitri Egorov, who openly supported the Russian Orthodox Church and had recently been arrested. They then proceeded to follow their plan of reorganizing the Society.[2]
Pontryagin was accused of anti-Semitism on several occasions.[2] For example, he attacked Nathan Jacobson for being a "mediocre scientist" representing the "Zionism movement", while both men were vice-presidents of the International Mathematical Union.[4][5] When a prominent Soviet Jewish mathematician, Grigory Margulis, was selected by the IMU to receive the Fields Medal at the upcoming 1978 ICM, Pontryagin, who was a member of the executive committee of the IMU at the time, vigorously objected.[6] Although the IMU stood by its decision to award Margulis the Fields Medal, Margulis was denied a Soviet exit visa by the Soviet authorities and was unable to attend the 1978 ICM in person.[6]
Pontryagin rejected charges of antisemitism in an article published in Science in 1979.[7] In his memoirs Pontryagin claims that he struggled with Zionism, which he considered a form of racism.[5]
Pontrjagin, L. (1939), Topological Groups, Princeton Mathematical Series, vol. 2, Princeton: Princeton University Press, MR0000265 (translated by Emma Lehmer)[8]
1952 - Foundations of Combinatorial Topology (translated from 1947 original Russian edition)[9] 2015 Dover reprint[10]
1962 - Ordinary Differential Equations (translated from Russian by Leonas Kacinskas and Walter B. Counts)[11]
^Blum, Edward Kenneth (December 1963). "Reviewed Work: The Mathematical Theory of Optimal Processes by Pontryagin, Boltyanskii, Gamkrelidze, Mishchenko". The American Mathematical Monthly. 70 (10): 1114–1116. doi:10.2307/2312867. JSTOR2312867.
