**SMS scnews item created by Stephan Tillmann at Thu 9 Oct 2014 1018**

Type: Seminar

Distribution: World

Expiry: 8 Jan 2015

**Calendar1: 22 Oct 2014 1100-1200**

**CalLoc1: Carslaw 535A**

Auth: tillmann@p710.pc (assumed)

### Geometry-Topology-Analysis Seminar

# The Bieri-Neumann-Strebel Invariant

### Adam Piggott (Bucknell)

GTA Seminar - Wednesday, 22 October, 11:00-12:00 in Carlaw 535A

##
The Bieri-Neumann-Strebel Invariant of the Pure Symmetric Automorphisms of a Right-Angled Artin Group

We compute the BNS-invariant for the pure symmetric automorphism groups of right-angled Artin groups. We use this calculation to show that the pure symmetric automorphism group of a right-angled Artin group is itself not a right-angled Artin group provided that its defining graph contains a separating intersection of links. This is joint work with Nic Koban (University of Maine, Farmington)

Please join us for lunch after the talk!