9 citations · 53 across the 17 of their papers we have counts for
17 papers
Ulam stability for classes of nuclear C*-algebras
Vadim Alekseev, Ilijas Farah, Andreas Thom
We study Ulam stability for approximate *-homomorphisms of C*-algebras. We prove stability results for several classes of nuclear C*-algebras with respect to von Neumann algebra ta…
Cubic maps from the group of order
Vadim Alekseev, Andreas Thom
The purpose of this note is to classify unital cubic maps from the cyclic group of order into an arbitrary non-abelian group. We show that the universal group admitting a unita…
Geometric property (T) for box spaces and sofic approximations
Vadim Alekseev, Stefan Drigalla
We prove that every sofic approximation of a property (T) group is approximately isomorphic to one having geometric property (T), and more generally, a box space of graphs which ha…
Amenability for unitary groups of C*-algebras
Vadim Alekseev, Max Schmidt, Andreas Thom
In this note we state a conjecture that characterizes unital C*-algebras for which the unitary group is amenable as a topological group in the norm topology. We prove the conjectur…
Maximal amenable subgroups of arithmetic groups
Vadim Alekseev, Alessandro Carderi
By classifying -maximal amenable subgroups of algebraic groups over a global field of characteristic zero, we obtain a complete classification of maximal amenable subgroups up t…
Maximal discrete subgroups in unitary groups of operator algebras
Vadim Alekseev, Andreas Thom
We show that if a group G is mixed-identity-free, then the projective unitary group of its group von Neumann algebra contains a maximal discrete subgroup containing G. The proofs a…
Sofic boundaries and a-T-menability
Vadim Alekseev, Leonardo Biz
We undertake a systematic study of the approximation properties of the topological and measurable versions of the coarse boundary groupoid associated to a sequence of finite graphs…
Representation theory of topological full groups of étale groupoids and paradoxicality
Vadim Alekseev, Martin Finn-Sell
We provide a unified treatment of several results concerning full groups of ample groupoids and paradoxical decompositions attached to them. This includes a criterion for the full…
A rigidity result for normalized subfactors
Vadim Alekseev, Rahel Brugger
We show a rigidity result for subfactors that are normalized by a representation of a lattice in a higher rank simple Lie group with trivial center into a finite factor. This i…
Uniqueness questions for C*-norms on group rings
Vadim Alekseev, David Kyed
We provide a large class of discrete amenable groups for which the complex group ring has several C*-completions, thus providing partial evidence towards a positive answer to a que…
On invariant random positive definite functions
Vadim Alekseev, Rahel Brugger
We give the definition of an invariant random positive definite function on a discrete group, generalizing both the notion of an invariant random subgroup and a character. We use v…
Sofic boundaries of groups and coarse geometry of sofic approximations
Vadim Alekseev, Martin Finn-Sell
Sofic groups generalise both residually finite and amenable groups, and the concept is central to many important results and conjectures in measured group theory. We introduce a to…
Non-amenable principal groupoids with weak containment
Vadim Alekseev, Martin Finn-Sell
We construct examples of principal groupoids that have weak containment but are not amenable, thus answering questions by Claire Anantharaman-Delaroche and Rufus Willett.
Quadratic Modules, C*-Algebras, and Free Convexity
Vadim Alekseev, Tim Netzer, Andreas Thom
Given a quadratic module, we construct its universal C*-algebra, and then use methods and notions from the theory of C*-algebras to study the quadratic module. We define residually…
On the first continuous -cohomology of free group factors
Vadim Alekseev
We prove that the first continuous -cohomology of free group factors vanishes. This answers a question by Andreas Thom regarding continuity properties of free difference quoti…
Measure continuous derivations on von Neumann algebras and applications to L^2-cohomology
Vadim Alekseev, David Kyed
We prove that norm continuous derivations from a von Neumann algebra into the algebra of operators affiliated with its tensor square are automatically continuous for both the stron…
Amenability and vanishing of L^2-Betti numbers: an operator algebraic approach
Vadim Alekseev, David Kyed
We recast the Foelner condition in an operator algebraic setting and prove that it implies a certain dimension flatness property. Furthermore, it is proven that the Foelner conditi…