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We completely classify the atomic summands in a graph product $(M,\varphi) = *_{v \in \mathcal{G}} (M_v,\varphi_v)$ of von Neumann algebras with faithful normal states. Each type I factor summand $(N,\psi)$ is a tensor product of type I…

Operator Algebras · Mathematics 2025-06-11 Ian Charlesworth , David Jekel

We study a generalization of free Poisson random measure by replacing the intensity measure with a n.s.f. weight $\varphi$ on a von Neumann algebra $M$. We give an explicit construction of the free Poisson random weight using full Fock…

Operator Algebras · Mathematics 2025-04-07 Zhiyuan Yang

We prove that every separable tracial von Neumann algebra embeds into a II$_1$ factor with property (T) which can be taken to have trivial outer automorphism and fundamental groups. We also establish an analogous result for the trivial…

Operator Algebras · Mathematics 2022-05-17 Ionut Chifan , Daniel Drimbe , Adrian Ioana

Given a discrete measured groupoid $\mathcal{G}$, we study properties of the corresponding von Neumann algebra $L(\mathcal{G})$ using the techniques of Popa's deformation/rigidity theory. More specifically, we define and study the Gaussian…

Operator Algebras · Mathematics 2025-09-19 Felipe Flores , James Harbour

Given an irreducible lattice $\Gamma$ in the product of higher rank simple Lie groups, we prove a co-finiteness result for the $\Gamma$-invariant von Neumann subalgebras of the group von Neumann algebra $\mathcal{L}(\Gamma)$, and for the…

Operator Algebras · Mathematics 2022-02-10 Mehrdad Kalantar , Nikolaos Panagopoulos

We study the $t$-deformation of gaussian von Neumann algebras. They appear as example in the theories of Interacting Fock spaces and conditionally free products. When the number of generators is fixed, it is proved that if $t$ sufficiently…

Operator Algebras · Mathematics 2007-05-23 Eric Ricard

In this paper, we present a new class of strongly singular maximal abelian subalgebras living inside the k-folded tensor product of the free group factor (on N>1 generators). A. Sinclair and R. Smith introduced the class of strongly…

Operator Algebras · Mathematics 2007-05-23 Teodor Stefan Bildea

We prove that any tensor product factorization with a commutative factor of a modular group algebra over a prime field comes from a direct product decomposition of the group basis. This extends previous work by Carlson and Kov\'acs for the…

Representation Theory · Mathematics 2026-04-07 Diego García-Lucas , Ángel del Río , Taro Sakurai

Developed in a series of seminal papers in the early 2010s, the tubal tensor framework provides a clean and effective algebraic setting for tensor computations, supporting matrix-mimetic features such as a tensor Singular Value…

Numerical Analysis · Mathematics 2025-06-05 Haim Avron , Uria Mor

Given a finite, directed, connected graph $\Gamma$ equipped with a weighting $\mu$ on its edges, we provide a construction of a von Neumann algebra equipped with a faithful, normal, positive linear functional…

Operator Algebras · Mathematics 2018-11-19 Michael Hartglass , Brent Nelson

The study of the defining equations of a finite set $\Gamma \subset \mathbb{P}^n$ in linearly general position has been actively attracted since it plays a significant role in understanding the defining equations of arithmetically…

Algebraic Geometry · Mathematics 2025-01-14 Jaeheun Jung , Euisung Park

We show that for any amenable group \Gamma and any Z\Gamma-module M of type FL with vanishing Euler characteristic, the entropy of the natural \Gamma-action on the Pontryagin dual of M is equal to the L2-torsion of M. As a particular case,…

Dynamical Systems · Mathematics 2013-10-10 Hanfeng Li , Andreas Thom

We single out a large class of groups ${\mathscr{M}}$ for which the following unique prime factorization result holds: if $\Gamma_1,\dots,\Gamma_n\in {\mathscr{M}}$ and $\Gamma_1\times\dots\times\Gamma_n$ is measure equivalent to a product…

Operator Algebras · Mathematics 2022-09-28 Daniel Drimbe

As an analogue of the topological boundary of discrete groups $\Gamma$, we define the noncommutative topological boundary of tracial von Neumann algebras $(M, \tau)$ and apply it to generalize the main results of [AHO23], showing that for a…

Operator Algebras · Mathematics 2025-07-29 Shuoxing Zhou

We show that if $\Gamma$ is an infinite finitely generated finitely presented sofic group with zero first $L^{2}$ Betti number then the von Neumann algebra $L(\Gamma)$ is strongly $1$-bounded in the sense of Jung. In particular,…

Operator Algebras · Mathematics 2016-09-16 D. Shlyakhtenko

Consider a compact locally symmetric space $M$ of rank $r$, with fundamental group $\Gamma$. The von Neumann algebra $\vn(\Gamma)$ is the convolution algebra of functions $f\in\ell_2(\Gamma)$ which act by left convolution on…

Operator Algebras · Mathematics 2013-02-25 Guyan Robertson

We discuss a Plancherel formula for countable groups, which provides a canonical decomposition of the regular representation of such a group $\Gamma$ into a direct integral of factor representations. Our main result gives a precise…

Operator Algebras · Mathematics 2020-10-27 Bachir Bekka

We describe the algebraic ingredients of a proof of the conjecture of Frenkel and Ip that the category of positive representations $\mathcal{P}_\lambda$ of the quantum group $U_q(\mathfrak{sl}_{n+1})$ is closed under tensor products. Our…

Representation Theory · Mathematics 2017-08-29 Gus Schrader , Alexander Shapiro

We study possible decompositions of totally decomposable algebras with involution, that is, tensor products of quaternion algebras with involution. In particular, we are interested in decompositions in which one or several factors are the…

Rings and Algebras · Mathematics 2015-12-04 Demba Barry

Using Popa's deformation/rigidity theory, we investigate prime decompositions of von Neumann algebras of the form $L(\mathcal{R})$ for countable probability measure preserving equivalence relations $\mathcal{R}$. We show that…

Operator Algebras · Mathematics 2015-10-30 Daniel J. Hoff