
Department of Mathematics
Special Lecture
Abstract by
Dr. Sam Evens
University of Arizona
Geometric formulas for multiplicities of representations.
It is well-known that formulas for decomposing the restriction
of a representation of a finite group to a subgroup involve
sums over conjugacy classes. We present here a generalization of
these formulas to a particular class of continuous groups (real
semisimple Lie groups), where sums over conjugacy classes are replaced
by computations in equivariant intersection cohomology. As a consequence,
we recover most of a well-known multiplicity one theorem for discrete
series in the space of $L^2$ functions on a semisimple symmetric space,
although our theorem also has multiplicity one implications for
certain representations in the space of smooth functions on a semisimple
symmmetric space. This talk is based on joint work with Ian Grojnowski.
- Friday - February 5, 1999 4:00 AM - 245 Altgeld Hall -
SPECIAL SEMINAR