'Daniel Grey ("Dan") Quillen' (born
June 21,
1940) is an
American mathematician and a
Fields Medalist.
From 1984 to 2006 he was the
Waynflete Professor of Pure Mathematics at
Magdalen College, Oxford. He is renowned for being the "prime architect" of higher
algebraic K-theory, for which he was awarded the
Cole Prize in
1975 and the Fields Medal in
1978.
Education and Career
Quillen was born in
Orange, New Jersey. He entered
Harvard University, where he earned both his
BA (1961) and his
PhD (1964), the latter of which was completed under the supervision of
Raoul Bott with a thesis in
partial differential equations.
Quillen obtained a position at the
Massachusetts Institute of Technology after completing his doctorate. However, he also spent a number of years at several other universities. This experience would prove to be important in influencing the direction of his research. He visited France twice: first as a
Sloan Fellow in Paris, during the academic year 1968–69, where he was greatly influenced by
Grothendieck, and then, during 1973–74, as a
Guggenheim Fellow. In 1969–70, he was a visiting member of the
Institute for Advanced Study at Princeton, where he came under the influence of
Michael Atiyah.
In 1978, Quillen received a Fields Medal at the
International Congress of Mathematicians held in
Helsinki.
His Ph.D. students include Kenneth Brown, Howard Hiller, Jeanne Duflot, Mark Baker,
Varghese Mathai (with whom he collaborated on the Mathai-Quillen formalism), and Jacek Brodzki.
Quillen retired at the end of
2006.
Selected Mathematical Contributions
Quillen's most celebrated contribution (mentioned specifically in his Fields medal citation) was his formulation of higher algebraic K-theory in
1972, a problem that had baffled mathematicians since algebraic K-theory was first formulated. This new tool, formulated in terms of homotopy theory, proved to be successful in formulating and solving major problems in algebra, particularly in ring theory and module theory. More generally, Quillen developed tools (especially his theory of model categories) which allowed algebreo-topological tools to be applied in other contexts
Before his ground-breaking work in defining higher algebraic K-theory, Quillen worked on the
Adams conjecture, formulated by
Frank Adams in
homotopy theory. His proof of the conjecture used techniques from the
modular representation theory of
groups, which he later applied to work on
cohomology of groups and
algebraic K-theory.
In related work, he also supplied a proof of
Serre's conjecture
about the trivality of algebraic
vector bundles on
affine space.
He is also the architect (along with
Dennis Sullivan) of
rational homotopy theory.
Reference
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