T. Akita (Hokkaido)

Title:
Central extensions of Coxeter groups and Artin groups

Abstract:
There is a unique nontrivial central extension of the symmetric group
on n letters by an infinite cyclic group. According to a result of
Andruskiewitsch and his collaborators, the central extension turns out
to be an intermediate group between the braid group on n strands and
the symmetric group. In this talk, I will explain this result and a
generalization to Coxeter groups and the corresponding Artin groups.
Homology stability will be also mentioned.