GROUP
FUNCTORS SEMINAR

"The Monomial Burnside Ring"

By

Laurence Barker

(Bilkent University)

Abstract: It is not true that every FG-module can be expressed as a
difference of permutation modules. However, a variant of that assertion does
hold when we extend the notion of a permutation set so that the finite group G
can twist points by roots of unity; for this,we require that the field F has enough roots of
unity. The algebraic structure for working with these twisted
permutation sets, introduced 40 years ago by Dress, is the monomial
Burnside ring. In this talk, after explaining the motivating context of
application, we place the monomial Burnside ring in a modern setting, realizing
it as a biset functor and as a Green functor.

Date:
Friday, April 6, 2012

Time: 13.40-15.30

Place: Mathematics Seminar Room,
SA-141

Tea and biscuits: after seminar