3 papers
math.GR2026
Hyperfiniteness of boundary actions via tree decompositions
Chris Karpinski, Bobby Miraftab
We study conditions for a countable group acting on a connected locally finite hyperbolic graph to induce a hyperfinite orbit equivalence relation on the Gromov boundary of the gra…
math.GR2026
Graphical small cancellation and hyperfiniteness of boundary actions
Chris Karpinski, Damian Osajda, Koichi Oyakawa
We study actions of (infinitely presented) graphical small cancellation groups on the Gromov boundaries of their coned-off Cayley graphs. We show that a class of graphical small ca…
math.GR2026
Conjugacy Problem for Dehn Twists of Free Products of Free Abelian Groups
Amir Y. Weiss Behar, Chris Karpinski, Bratati Som
We show solubility of the conjugacy problem for Dehn twist automorphisms of finitely generated free products of free abelian groups.