Title: Intermediate von Neumann subalgebras arising from multiple transitive actions
Speaker: Yongle Jiang（Dalian University of Technology）
Time: 16:00-17:00,July31
Location: Tecent Meeting, Tecent Meeting ID: 317 436 538, Password: 200731
Abstract: In this talk, we discuss the following problem: Let $G \curvearrowright X$ be a faithful n-transitive action on an infinite set X for some positive integer n larger than 3. Denote by H the stabilizer group of any point in X. Can we describe all intermediate von Neumann subalgebras between L(H) and L(G)?
We will discuss motivations to study this question, present an affirmative answer for n larger than 3, and discuss recent progress for n=3 and n=2. As applications, we show L(SL2(Z)) is a maximal Haagerup von Neumann subalgebra in $L(Z^2 \rtimes SL_2 (Z))$ and present “easy” but less satisfactory answers to a question of Prof. Ge. Part of this talk is based on joint work with Prof. Adam Skalski.
Meeting Link: https://meeting.tencent.com/s/acDBsLBfGHyl
Slides: 
Intermediate von Neumann subalgebras arising from multiple transitive actions.pdf
