Lev Semёnovič Pontrjagin (Лев Семёнович Понтрягин) was an influential Soviet mathematician working in Moscow. His main works till the late 1940s were in topology, especially the study of topological groups (including study of Pontrjagin duality) and algebraic topology in which he also explored applications of differentiable manifolds for computation of homotopy groups; including the introduction of framed cobordism in that work. After the success of the French mathematical school in the late 1940s in introducing new methods of sheaf theory, which Pontrjagin did not like as less direct than the more intuitive geometric methods he was master of, and after some pressure from the government, Pontrjagin switched into applied mathematics where he did some fundamental work, especially in optimization theory.
Pontrjagin was a full member of the (Soviet) Academy of Sciences. He was blind since the age of 14.
Introducing Pontryagin's theorem – the bijection between cobordism classes of normally framed submanifolds of a closed smooth manifold and its Cohomotopy-sets, established via the Pontryagin-Thom collapse/Cohomotopy charge – and its application to the computation of
the first stable homotopy group of spheres:
and the second stable homotopy group of spheres:
Lev Pontrjagin, Classification of continuous maps of a complex into a sphere, Communication II, Dokl. Akad. Nauk SSSR 19 (1938), 361-363
(this article contains a famous mistake, see Hopkins‘s talk at Atiyah’s 80th Birthday conference, see slide 8, 9:45)
Lev Pontryagin, Homotopy classification of mappings of an (n+2)-dimensional sphere on an n-dimensional one, Doklady Akad. Nauk SSSR (N.S.) 19 (1950), 957–959, (Russian) (pdf)
(this article fixes the mistake)
all three of which are available in English translation in Gamkrelidze 86.
A comprehensive account of this cobordism theory/stable homotopy theory via Pontryagin's theorem (now mostly: “Pontryagin-Thom theorem”) is then given in:
Introducing the Pontrjagin product:
Selected articles:
Last revised on February 4, 2021 at 06:20:49. See the history of this page for a list of all contributions to it.