Graphs, surfaces, and cube complexes
11 July 2018
Abstract: A Schottky set is the complement in S2 of at least 3 disjoint round open discs. Examples include the Sierpinski carpet and the Apollonian gasket. A relatively hyperbolic group pair (G,P) has a boundary ∂(G,P) which is an invariant of the group pair. When this boundary is a Schottky set, what does this tell us about the group pair? We will show that in this situation the incidence group has 1,2 or infinitely many components and show that in the one-component case, G is virtually a free product of infinite cyclic groups and surface groups.
This is joint work with P. Haissinsky and L. Paoluzzi.