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Related papers: Full factors and co-amenable inclusions

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We are able to explicitly compute the bimodule structure of von Neumann algebra inclusions in handle constructions, which arise as inductive limits of iterated amalgamated free products not elementarily equivalent to $L(\mathbb{F}_2)$. Our…

Operator Algebras · Mathematics 2026-02-03 David Gao , David Jekel , Srivatsav Kunnawalkam Elayavalli , Gregory Patchell

In this paper, we will show that if for every nonlinear complex irreducible character of a finite group G, some multiple of it is induced from an irreducible character of some proper subgroup of G, then G is solvable. This is a…

Group Theory · Mathematics 2012-11-09 Tung Le , Jamshid Moori , Hung P. Tong-Viet

Given a dense additive subgroup $G$ of $\mathbb R$ containing $\mathbb Z$, we consider its intersection $\mathbb G$ with the interval $[0,1[$ with the induced order and the group structure given by addition modulo $1$. We axiomatize the…

Logic · Mathematics 2017-07-20 Luc Bélair , Françoise Point

A similarity structure on a connected manifold M is a Riemannian metric on its universal cover such that the fundamental group of M acts by similarities. If the manifold M is compact, we show that the universal cover admits a de Rham…

Differential Geometry · Mathematics 2019-04-26 Mickaël Kourganoff

We show that coincidence of the full and reduced crossed product $C^\ast$-algebras of a group action on a unital commutative $C^\ast$-algebra implies amenability of the action whenever the group is exact. This is a partial answer to a…

Operator Algebras · Mathematics 2012-04-16 Masayoshi Matsumura

Let $\mathcal{M}$ be a type II$_1$ von Neumann factor and let $S(\mathcal{M})$ be the associated Murray-von Neumann algebra of all measurable operators affiliated to $\mathcal{M}.$ We extend a result of Kadison and Liu \cite{KL} by showing…

Operator Algebras · Mathematics 2020-01-29 Aleksey Ber , Karimbergen Kudaybergenov , Fedor Sukochev

For a domain $G$ in the one-point compactification $\overline{\mathbb{R}}^n = \mathbb{R}^n \cup \{ \infty\}$ of $\mathbb{R}^n, n \ge 2$, we characterize the completeness of the modulus metric $\mu_G$ in terms of a potential-theoretic…

Complex Variables · Mathematics 2022-06-06 Toshiyuki Sugawa , Matti Vuorinen , Tanran Zhang

We undertake a comprehensive study of structural properties of graph products of von Neumann algebras equipped with faithful, normal states, as well as properties of the graph products relative to subalgebras coming from induced subgraphs.…

It is known that every semigroup of normal completely positive maps of a von Neumann can be ``dilated" in a particular way to an E_0-semigroup acting on a larger von Neumann algebra. The E_0-semigroup is not uniquely determined by the…

funct-an · Mathematics 2008-02-03 William Arveson

Submodular functions are known to satisfy various forms of fractional subadditivity. This work investigates the conditions for equality to hold exactly or approximately in the fractional subadditivity of submodular functions. We establish…

Information Theory · Computer Science 2025-06-24 Gunank Jakhar , Gowtham R. Kurri , Suryajith Chillara , Vinod M. Prabhakaran

Recently C. Houdayer and Y. Isono have proved among other things that every biexact group $\Gamma$ has the property that for any non-singular strongly ergodic action $\Gamma\curvearrowright (X,\mu)$ on a standard measure space the group…

Operator Algebras · Mathematics 2019-02-20 Narutaka Ozawa

The Peterson-Thom conjecture asserts that any diffuse, amenable subalgebra of a free group factor is contained in a unique maximal amenable subalgebra. This conjecture is motivated by related results in Popa's deformation/rigidity theory…

Operator Algebras · Mathematics 2022-03-15 Ben Hayes

Given an irreducible local conformal net A of von Neumann algebras on the circle and a finite-index conformal subnet B of A, we show that A is completely rational iff B is completely rational. In particular this extends a result of F. Xu…

Operator Algebras · Mathematics 2011-04-06 Roberto Longo

Given a von Neumann algebra $M$ we consider the central extension $E(M)$ of $M.$ We describe class of von Neumann algebras $M$ for which the algebra $E(M)$ coincides with the algebra $S(M)$ -- the algebra of all measurable operators with…

Operator Algebras · Mathematics 2011-10-24 S. Albeverio , K. K. Kudaybergenov , R. T. Djumamuratov

We investigate the position of amenable subalgebras in arbitrary amalgamated free product von Neumann algebras $M = M_1 \ast_B M_2$. Our main result states that under natural analytic assumptions, any amenable subalgebra of $M$ that has a…

Operator Algebras · Mathematics 2019-01-09 Rémi Boutonnet , Cyril Houdayer

We define the completion of an associative algebra $A$ in a set $M=\{M_1,\dots,M_r\}$ of $r$ right $A$-modules in such a way that if $\mathfrak a\subseteq A$ is an ideal in a commutative ring $A$ the completion $A$ in the (right) module…

Algebraic Geometry · Mathematics 2024-10-23 Arvid Siqveland

Let $M$ be a finite von Neumann algebra with the Haagerup property, and let $G$ be a compact group that acts continuously on $M$ and that preserves some finite trace $\tau$. We prove that if $\Gamma$ is a countable subgroup of $G$ which has…

Operator Algebras · Mathematics 2007-05-23 Paul Jolissaint

Starting from a (small) rigid C$^*$-tensor category $\mathscr{C}$ with simple unit, we construct von Neumann algebras associated to each of its objects. These algebras are factors and can be either semifinite (of type II$_1$ or II$_\infty$,…

Operator Algebras · Mathematics 2019-08-06 Luca Giorgetti , Wei Yuan

A subalgebra $\mathcal{A}$ of a $C^*$-algebra $\mathcal{M}$ is logmodular (resp. has factorization) if the set $\{a^*a; a\text{ is invertible with }a,a^{-1}\in\mathcal{A}\}$ is dense in (resp. equal to) the set of all positive and…

Operator Algebras · Mathematics 2021-01-05 B. V. Rajarama Bhat , Manish Kumar

In [2] Su Gao proves that the following are equivalent for a countable $M$ (cf. theorem 1.2 too): (I)There is an uncountable model of the Scott sentence of $M$. (II) There exists some $j\in \overline{Aut(M)}\setminus Aut(M)$, where…

Logic · Mathematics 2015-06-09 Ioannis Souldatos