Title: Comparison property for amenable group actions

Speaker:   Prof. Guohua Zhang  ( Fudan University )

Time: Thur, Apr.8 2021, PM: 15:00-16:00

Location: Tencent Conference

Meeting  Number: 970890000

Password: 654321

Inviter: Prof. Dongkui Ma

Abstract:

      Let a countable discrete group G act on a zero-dimensional compact metric space X. We say that the action admits comparison if for any clopen sets A and B, the condition, that for every G-invariant measure m on X we have the sharp inequality m(A)< m(B), implies that A is subequivalent to B, that is, there exists a finite clopen partition A1, ..., Ak for A, and elements g1, ..., gk in G such that g1(A1), ..., gk(Ak) are disjointclopen subsets of B. We prove this property for actions of groups whose every finitely generated subgroup has subexponential growth. This is a joint work with Professor Tomasz Downarowicz.