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Related papers: A Kurosh type theorem for type II_1 factors

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Let $L_1$, $L_2$ $L_3$ be integer linear functions with no fixed prime divisor. We show there are infinitely many $n$ for which the product $L_1(n)L_2(n)L_3(n)$ has at most 7 prime factors, improving a result of Porter. We do this by means…

Number Theory · Mathematics 2015-06-05 James Maynard

We establish a platform to transfer $L_p$-completely bounded maps on tensor products of von Neumann algebras to $L_p$-completely bounded maps on the corresponding amalgamated free products. As a consequence, we obtain a H\"ormander-Mikhlin…

Operator Algebras · Mathematics 2021-03-18 Tao Mei , Éric Ricard , Quanhua Xu

We introduced a non-symmetric tensor product of any two states or any two representations of Cuntz-Krieger algebras associated with a certain non-cocommutative comultiplication in previous our work. In this paper, we show that a certain set…

Operator Algebras · Mathematics 2008-05-07 Katsunori Kawamura

Let M and N be Orlicz functions. We establish some combinatorial inequalities and show that the product spaces l^n_M(l^n_N) are uniformly isomorphic to subspaces of L_1 if M and N are "separated" by a function t^r, 1<r<2.

Functional Analysis · Mathematics 2012-04-27 Joscha Prochno , Carsten Schuett

We give a description of operator algebras of free wreath products in terms of fundamental algebras of graphs of operator algebras as well as an explicit formula for the Haar state. This allows us to deduce stability properties for certain…

Operator Algebras · Mathematics 2024-02-22 Pierre Fima , Arthur Troupel

We establish a crossed product decomposition theorem for stabilized Cuntz--Pimsner algebras. This result extends Cuntz's classical decomposition for the Cuntz algebras $\mathcal{O}_n$ and reveals an implicit symmetric structure within…

Operator Algebras · Mathematics 2026-05-21 Miho Mukohara , Yuhei Suzuki

We show that a factor $M$ is full if and only if the $C^*$-algebra generated by its left and right regular representations contains the compact operators. We prove that the bicentralizer flow of a type $\mathrm{III}_1$ factor is always…

Operator Algebras · Mathematics 2018-12-03 Amine Marrakchi

We prove that the Waldhausen nilpotent class group of an injective index 2 amalgamated free product is isomorphic to the Farrell-Bass nilpotent class group of a twisted polynomial extension. As an application, we show that the Farrell-Jones…

K-Theory and Homology · Mathematics 2016-05-18 James F. Davis , Qayum Khan , Andrew Ranicki

We obtain a Lie theoretic intrinsic characterization of the connected and simply connected solvable Lie groups whose regular representation is a factor representation. When this is the case, the corresponding von Neumann algebras are…

Representation Theory · Mathematics 2024-05-15 Ingrid Beltita , Daniel Beltita

Recently, Boutonnet, Chifan, and Ioana proved that McDuff's family of continuum many pairwise nonisomorphic separable II$_1$ factors are in fact pairwise non-elementarily equivalent by proving that any ultrapowers of two distinct members of…

Logic · Mathematics 2016-02-05 Isaac Goldbring , Bradd Hart

We show that given any subgroup F of R_+ which is either countable or belongs to a certain "large" class of uncountable subgroups, there exist continuously many free ergodic probability measure preserving actions \sigma_i of the free group…

Operator Algebras · Mathematics 2015-05-13 Sorin Popa , Stefaan Vaes

We introduce pseudofinite W*-probability spaces. These are W*-probability spaces that are elementarily equivalent to Ocneanu ultraproducts of finite-dimensional von Neumann algebras equipped with arbitrary faithful normal states. We are…

Operator Algebras · Mathematics 2026-02-16 Jananan Arulseelan

In this informal expository note, we present a universal, formulaic construction of the free product of rigid $C^*$-2-categories. This construction allows for a straightforward, purely categorical formulation of the free composition of…

Operator Algebras · Mathematics 2020-09-01 Matthias Valvekens

Can one detect free products of groups via their profinite completions? We answer positively among virtually free groups. More precisely, we prove that a subgroup of a finitely generated virtually free group $G$ is a free factor if and only…

Group Theory · Mathematics 2024-08-28 Alejandra Garrido , Andrei Jaikin-Zapirain

In this paper we study conditions under which, for an inclusion of finite von Neumann algebras $N \subseteq M$, we have the reduced amalgamated free product $\ast_N M$ is embeddable into $(R \bar{\otimes} N_1)^\omega$ for some other finite…

Operator Algebras · Mathematics 2021-12-07 Weichen Gao , Marius Junge , Weichen Gao

This paper addresses an investigation on a factorization method for difference equations. It is proved that some classes of second order linear difference operators, acting in Hilbert spaces, can be factorized using a pair of mutually…

Mathematical Physics · Physics 2017-09-25 Alina Dobrogowska , Mahouton Norbert Hounkonnou

We investigate factoriality, Connes' type ${\rm III}$ invariants and fullness of arbitrary amalgamated free product von Neumann algebras using Popa's deformation/rigidity theory. Among other things, we generalize many previous structural…

Operator Algebras · Mathematics 2025-07-17 Cyril Houdayer , Yusuke Isono

We give a complete answer to the questions of factoriality, type classification and fullness for arbitrary free product von Neumann algebras.

Operator Algebras · Mathematics 2019-05-21 Yoshimichi Ueda

Let $G$ be a $(2,m,n)$-group and let $x$ be the number of distinct primes dividing $\chi$, the Euler characteristic of $G$. We prove, first, that, apart from a finite number of known exceptions, a non-abelian simple composition factor $T$…

Group Theory · Mathematics 2014-02-26 Nick Gill

Let $\M$ be a type ${\rm II_1}$ factor and let $\tau$ be the faithful normal tracial state on $\M$. In this paper, we prove that given finite elements $X_1,\cdots X_n \in \M$, there is a finite decomposition of the identity into $N \in…

Operator Algebras · Mathematics 2023-03-21 Shilin Wen , Junsheng Fang , Zhaolin Yao