# University of Toronto's Symplectic Geometry Seminar

March 24, 2003, 2pm

SS5017A

## Eckhard Meinrenken

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Toronto

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** Abstract: **
The classical Chern-Weil theory of characteristic classes
associates to every principal bundle over a space B
a homomorphism from the ring of invariant polynomials into the
cohomology ring of B. It was observed by Cartan that the
Chern-Weil construction admits a very nice algebraic
reformulation, entering his model for the equivariant
cohomology of a space. In this talk I will review the
Chern-Weil-Cartan theory, and show how to apply these ideas
in the context of Lie algebras. Specifically, one obtains
a new interpretation of Duflo's theorem for the special case
of quadratic Lie algebras.