Michael Barr is the Peter Redpath Emeritus Professor of Pure Mathematics at McGill University. Although his earlier work was in homological algebra, his principal research area for a number of years has been category theory. He is well known to theoretical computer scientists for his book
as well as for the development of star-autonomous categories and Chu spaces which have found various applications in computer science. His books
$*$-autonomous categories,
M. Barr, C. Wells, Toposes, Triples, and Theories, Grundlehren der math. Wissenschaften 278. Springer-Verlag, 1983, ftp, web, pdf, which has been republished in the TAC reprints series.
Acyclic Models, CRM monographs, 2002,
are aimed at more specialized audiences.
He is on the editorial boards of Mathematical Structures in Computer Science and the electronic journal Homology, Homotopy and Applications, and is editor of the electronic journal Theory and Applications of Categories. Michael Barr has much advocated the methods of his late student Jon Beck, involving monads, especially monadicity criteria and monadic cohomology.
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