Sven Raum

activity

20102025

most citedAmalgamated free product type III factors with at most one Cartan subalgebra

29 citations · 116 across the 26 of their papers we have counts for

collaborators

Showing 2016Show all

3 papers · 1 filter

math.OA2016★ 5 cited

Higher l^2-Betti numbers of universal quantum groups

Julien Bichon, David Kyed, Sven Raum

We calculate all $ℓ^{2}$ -Betti numbers of the universal discrete Kac quantum groups $U^_{n}^{+}$ as well as their full half-liberated counterparts $U^_{n}^{*}$ .

math.GR2016

Locally compact groups acting on trees, the type I conjecture and non-amenable von Neumann algebras

Cyril Houdayer, Sven Raum

We address the problem to characterise closed type I subgroups of the automorphism group of a tree. Even in the well-studied case of Burger-Mozes' universal groups, non-type I crit…

math.OA2016★ 1 cited

On the l^2-Betti numbers of universal quantum groups

David Kyed, Sven Raum

We show that the first $ℓ^{2}$ -Betti number of the duals of the free unitary quantum groups is one, and that all $ℓ^{2}$ -Betti numbers vanish for the duals of the quantum automor…