Nathan Mendelsohn

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Nathan Saul Mendelsohn (born April 14, 1917 in Brooklyn , † July 4, 2006 in Toronto ) was a Canadian mathematician , professor at the University of Manitoba . He dealt with group theory , geometry and combinatorics .

Mendelsohn around 1995

Mendelsohn moved with his parents (Jewish immigrants from Romania and Galicia) to Toronto in 1918, where he studied mathematics and received his doctorate in 1941 under Richard Brauer and Gilbert de Beauregard Robinson ( A Group-Theoretic Characterization of the General Projective Collineation Group ). As a student he successfully participated in the Putnam competition in 1938 (another team member at the University of Toronto was Irving Kaplansky ). During the Second World War he worked as a cryptologist. In 1945 he became a professor at Queen's University in Kingston and in 1947 at the University of Manitoba, where he remained until his retirement in 2005. He also worked for Rand Corporation in the early 1960s .

The Dulmage-Mendelsohn decomposition to generate maximum matchings bipartite graphs is named after him. It has applications in finite element mesh generation. Among other things, he dealt with Steiner-Triple-Systems and their generalizations, orthogonal Latin squares , block plans , quasi-groups and groupoids . For a work with Diane Johnson and AL Dulmage from 1961 ( Orthomorphisms of groups and orthogonal latin squares , Canad. J. Math., Vol. 13, 1961, pp. 356-372) he received the Tory Medal of the Royal Society of Canada. In it they constructed five orthogonal Latin squares in pairs and came (according to the 1979 laudation) closer than anyone else to the solution of the problem of constructing a projective plane of composite order . His application of algebraic techniques in combinatorics and vice versa of combinatorics in algebra led to the establishment of a separate branch of combinatorics (combinatorial universal algebra).

From 1969 to 1971 he was President of the Canadian Mathematical Society. He was a Fellow of the Royal Society of Canada (1957), whose Henry Marshall Tory Medal he received in 1979. In 1999 he received the Order of Canada and in 1975 the Jeffery Williams Prize .

In the early 1950s he was also an award-winning amateur magician, specifically with card tricks (and also published on math from card tricks). He was married with two sons, one of whom Eric Mendelsohn became a math professor at the University of Toronto.

Web links

Individual evidence

  1. ^ Proc. Nat. Acad. Sci., Vol. 30, 1944, pp. 279-283
  2. ^ Mathematics Genealogy Project
  3. ↑ AL Dulmage, NS Mendelsohn Coverings of bipartite graphs . Canad. J. Math., Vol. 10, 1958, pp. 517-534
personal data
SURNAME Mendelsohn, Nathan
ALTERNATIVE NAMES Mendelsohn, Nathan Saul
BRIEF DESCRIPTION Canadian mathematician
DATE OF BIRTH April 14, 1917
PLACE OF BIRTH Brooklyn
DATE OF DEATH 4th July 2006
Place of death Toronto