3 papers
math.GR2026
Boundary Dynamics, Cubical Actions, and Infinite Girth
Tattwamasi Amrutam, Arka Banerjee, Daniel L. Gulbrandsen +1
We develop two methods for proving infinite girth from boundary dynamics. First, we use topologically free extreme boundary actions to give a boundary-dynamical proof of infinite g…
math.GR2024
On the Girth of Groups acting on CAT(0) cube complexes
Arka Banerjee, Daniel Gulbrandsen, Pratyush Mishra +1
We obtain a sufficient condition for lattices in the automorphism group of a finite dimensional CAT(0) cube complex to have infinite girth. As a corollary, we get a version of Girt…
math.GT2023
A generalized theory of expansions and collapses with applications to Z-compactification
Craig R. Guilbault, Daniel Gulbrandsen
We generalize the dual notions of "expansion" and "collapse" so they can be applied to arbitrary metric spaces. We also expand the theory to allow for infinitely many such moves. T…