Closure of approximate L2L^2-rigidity under joins with diffuse intersection

Let MM be a II1\rm II_1 factor and let Q1,Q2MQ_1,Q_2\leq M be von Neumann subalgebras such that QiMQ_i\leq M is approximately L2L^2-rigid for i=1,2i=1,2. Suppose that Q1Q2Q_1\cap Q_2 is diffuse. Approximate L2L^2-rigidity join conjecture. Then Q1Q2MQ_1\vee Q_2\leq M is approximately L2L^2-rigid.

This is the von Neumann algebra analogue of a result of Peterson and Thom for subgroups with infinite intersection. A positive solution would imply the stated amenability conjecture for subalgebras of L(F2)L(\mathbb F_2), but the source provides no resolution.

Sources & referencesView supporting material

Primary source

Rolando de Santiago, Ben Hayes, Daniel J. Hoff and Thomas Sinclair, “Maximal rigid subalgebras of deformations and L^2-cohomology”, arXiv:1909.03570 (2020).

Progress summary

Never refreshed

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Solutions 0

No solutions have been posted yet.