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Solomon Lefschetz

Solomon Lefschetz
Solomon Lefschetz.jpg
Born (1884-09-03)3 September 1884
Moscow, Russian Empire
Died 5 October 1972(1972-10-05) (aged 88)
Princeton, New Jersey, U.S.
Nationality American
Fields Algebraic topology
Institutions University of Nebraska
University of Kansas
Princeton University
Alma mater École Centrale Paris
Clark University
Doctoral advisor William Edward Story
Doctoral students Edward Begle
Richard Bellman
Felix Browder
Clifford Dowker
George F. D. Duff
Ralph Fox
Ralph Gomory
John McCarthy
Robert Prim
Paul A. Smith
Norman Steenrod
Clifford Truesdell
Albert W. Tucker
John Tukey
Henry Wallman
Shaun Wylie
Known for Lefschetz fixed point theorem
Picard–Lefschetz theory
Lefschetz connection
Lefschetz hyperplane theorem
Lefschetz duality
Lefschetz manifold
Lefschetz number
Lefschetz zeta function
Lefschetz pencil
Lefschetz theorem on (1,1)-classes
Notable awards Bôcher Memorial Prize (1924)
National Medal of Science (1964)
Leroy P. Steele Prize (1970)
Fellow of the Royal Society

Solomon Lefschetz (Russian: Соломо́н Ле́фшец; 3 September 1884 – 5 October 1972) was an American mathematician who did fundamental work on algebraic topology, its applications to algebraic geometry, and the theory of non-linear ordinary differential equations.

He was born in Moscow into a Jewish family (his parents were Ottoman citizens) who moved shortly after that to Paris. He was educated there in engineering at the École Centrale Paris, but emigrated to the USA in 1905.

He was badly injured in an industrial accident in 1907, losing both hands. He moved towards mathematics, receiving a Ph.D. in algebraic geometry from Clark University in Worcester, Massachusetts in 1911. He then took positions in University of Nebraska and University of Kansas, moving to Princeton University in 1924, where he was soon given a permanent position. He remained there until 1953.

In the application of topology to algebraic geometry, he followed the work of Charles Émile Picard, whom he had heard lecture in Paris at the École Centrale Paris. He proved theorems on the topology of hyperplane sections of algebraic varieties, which provide a basic inductive tool (these are now seen as allied to Morse theory, though a Lefschetz pencil of hyperplane sections is a more subtle system than a Morse function because hyperplanes intersect each other). The Picard–Lefschetz formula in the theory of vanishing cycles is a basic tool relating the degeneration of families of varieties with 'loss' of topology, to monodromy. His book L'analysis situs et la géométrie algébrique from 1924, though opaque foundationally given the current technical state of homology theory, was in the long term very influential (one could say that it was one of the sources for the eventual proof of the Weil conjectures, through SGA7 also for the study of Picard groups of Zariski surface). In 1924 he was awarded the Bôcher Memorial Prize for his work in mathematical analysis.


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