# Jerusalem Mathematics Colloquium

Thursday, 27th November 2008, 4:00 pm

Mathematics Building, Lecture Hall 2

##

Jean-Claude Hausmann

(University of Geneva)

"Conjugation spaces"

** Abstract: **

There are classical examples of spaces X with an
involution \tau whose mod 2-cohomology ring ressembles, as closely as
possible, that of their fixed point set X^\tau: there is a ring
isomorphism \kappa: H^{2*}(X)\isom{}H^*(X^\tau), halving the degree. Such
examples include complex Grassmannians, toric manifolds, polygon
spaces, etc.
In this talk, we show that the ring isomorphism \kappa is part
of an interesting structure in equivariant cohomology. Such spaces are
called *conjugation spaces* and they enjoy remarkable properties. There
are many examples, coming for instance from Lie groups and Hamiltonian
geometry.

Light refreshments will be served in the faculty lounge at 3:30.

List of talks, 2008-09

Archive of talks