成人大片

Title: Hyperfiniteness of boundary actions of graphical small cancellation groups

Abstract: Given a Gromov hyperbolic space equipped with an action of a group by isometries, one can study the orbit equivalence relation of the induced action of the group on the Gromov boundary of the space. Marquis and Sabok proved that the action of hyperbolic groups on their Gromov boundaries turns out to have the property that the orbits can be arranged into lines in a consistent manner, a property known as hyperfiniteness. We show that (infinitely presented) graphical small cancellation groups exhibit a similar phenomenon, inducing hyperfinite orbit equivalence relations on the boundaries of their natural hyperbolic Cayley graphs. This is joint work with Damian Osajda and Koichi Oyakawa.

We will gather for teatime in the lounge after the talk.