7 papers
Connes-embeddability and twisted group von Neumann algebras
Soham Chakraborty, Felipe Flores
We call a countable discrete group cocycle-hyperlinear if all its twisted group von Neumann algebras are Connes-embeddable. We show that the class of cocycle-hyperlinear groups inc…
Algorithm Support for Graph Databases, Done Right
Daan de Graaf, Robert Brijder, Soham Chakraborty +3
Graph database query languages cannot express algorithms like PageRank, forcing costly data wrangling, while existing solutions such as algorithm libraries, vertex-centric APIs, an…
Kesten's criterion for discrete probability measure-preserving groupoids
Soham Chakraborty, Milan Donvil, Felipe Flores +1
Inspired by Kesten's criterion for the amenability of groups, we establish a characterization of the amenability of discrete probability measure-preserving groupoids in terms of th…
On ergodicity of linear actions on and factoriality of group von Neumann algebras
Soham Chakraborty, Chinmay Tamhankar
We give some natural conditions on actions of discrete countable groups on abelian locally compact groups of Lie type that imply factoriality of the group von Neumann algebras of t…
The Choquet-Deny Property for Groupoids
Tey Berendschot, Soham Chakraborty, Milan Donvil +2
A countable discrete group is called Choquet-Deny if for any non-degenerate probability measure on the group, the corresponding space of bounded harmonic functions is trivial. Buil…
Factoriality of groupoid von Neumann algebras
Tey Berendschot, Soham Chakraborty, Milan Donvil +1
We give a characterisation of factoriality of the groupoid von Neumann algebra associated to a discrete measured groupoid . We introduce the notio…
A type III factor with the smallest outer automorphism group
Soham Chakraborty
The canonical modular homomorphism provides an embedding of into the outer automorphism group Out() of any type III factor . We provide an explicit constru…