3-Manifold Seminar: Bass-Serre Theory and PSL(2,Qp)

Seminar | October 30 | 2:10-3:30 p.m. | 939 Evans Hall


 Department of Mathematics

We will begin by filling in some details from last time, and describe the p-adic tree in more detail. We'll briefly discuss buildings, complexes of groups, and cubulated groups, which can be viewed as generalizations of Bass-Serre theory. It is a consequence of Bass-Serre theory that finitely generated groups which act discretely on a locally finite tree have a finite index subgroup which is a finitely generated free group. We'll consider the question of whether a one-ended hyperbolic group can act discretely on a product of trees, and examine a particular example proposed by Long and Reid.