|Alma mater||Harvard University|
|Spouse(s)||Natalie Zemon Davis|
|Institutions||University of Toronto|
|Thesis||Lattices and Modal Operators (1950)|
|Doctoral advisor||Garrett Birkhoff|
He was born in Ithaca, New York, to parents Horace B. Davis and Marian R. Davis. In 1948 he married Natalie Zemon Davis; they have three children. He was a member of the CPUSA and he was fired from the University of Michigan and jailed for his beliefs.
He moved to Canada in 1962 and began teaching at the University of Toronto. A lecture in honour of his stand for his beliefs is now held at the university that fired him.
In 1950 he received a doctorate in mathematics from Harvard University.
His principal research investigations involve linear algebra and operator theory in Hilbert space. Furthermore, he has made contributions to numerical analysis, geometry, and algebraic logic. He is one of the eponyms of the Davis–Kahan theorem and Bhatia–Davis inequality (along with Rajendra Bhatia). The Davis–Kahan–Weinberger dilation theorem is one of the landmark results in the dilation theory of Hilbert space operators and has found applications in many different areas. A PhD thesis titled "Backward Perturbation and Sensitivity Analysis of Structured Polynomial Eigenvalue Problem" is dedicated to this theorem. Davis has written around eighty research papers in mathematics.
Davis was a professor in the mathematics department of University of Michigan, working alongside Wilfred Kaplan. In the Mathematics Genealogy Project, he is listed as having 15 PhD (1964-2001), and 213 PhD descendants of his former doctoral students, with 107 being of them from his student John Benedetto (PhD 1964).
He is currently one of the co-Editors-in-Chief of the Mathematical Intelligencer. In 2012 he became a fellow of the American Mathematical Society. He is part of the 2019 class of fellows of the Association for Women in Mathematics.
He began his writing career in Astounding Science Fiction in 1946. From 1946 through 1962 he produced a spate of science fiction stories, mostly published there. One of the earliest, published May 1946, was The Nightmare, later the lead story in A Treasury of Science Fiction, edited by Groff Conklin; it argued for a national policy of decentralizing industry to evade nuclear attacks by terrorists. He also issued the fanzine "Blitherings" in the 1940s.
He attended Torcon I, the 6th World Science Fiction Convention in 1948, appeared at the 2010 SFContario science fiction convention, and was Science Guest of Honor at the 2013 SFContario science fiction convention.
Davis—along with two other professors, Mark Nickerson and Clement Markert—refused to cooperate with the House Unamerican Activities Committee and was subsequently dismissed from the University of Michigan. Davis was then sentenced to a six-month prison term where he was able to do some research. A paper from this era has the following acknowledgement:
The Federal government released Davis from prison in 1960. After his release, Davis moved to Canada, where he currently resides.
In 1991, the University of Michigan Senate initiated the annual Davis, Markert, Nickerson Lecture on Academic and Intellectual Freedom. Recent speakers have included: Cass Sunstein (2008), Nadine Strossen (2007), Bill Keller (2006), Floyd Abrams (2005), and Noam Chomsky (2004).