Return to Colloquia & Seminar listing
Complexes of Groups
Student-Run Geometry/Topology Seminar| Speaker: | Gabe Amos, UC Davis |
| Location: | 2112 MSB |
| Start time: | Tue, Apr 27 2010, 12:10PM |
A complex of groups is an algebraic object that generalizes the notions of amalgamation and HNN extensions of groups. Just as graphs of groups arise by studying group actions on trees, complexes of groups arise by studying group actions on 1-connected complexes of higher dimension. However, unlike the 1-dimensional case, there is no bijection between complexes of groups and group actions on complexes for dimension higher than 2. We'll discuss some examples in one and two dimensions, and address the question of when a complex of groups arises from a group action.