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Related papers: Non-Archimedean Group Algebras with Baer Reduction…

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We define nonselfadjoint operator algebras with generators $L_{e_1},..., L_{e_n}, L_{f_1},...,L_{f_m}$ subject to the unitary commutation relations of the form \[ L_{e_i}L_{f_j} = \sum_{k,l} u_{i,j,k,l} L_{f_l}L_{e_k}\] where $u=…

Operator Algebras · Mathematics 2007-05-23 Stephen C. Power , Baruch Solel

We show that if an infinite-dimensional Banach space X has a symmetric basis then there exists a bounded, linear operator R : X --> X such that the set A = {x in X : ||R^n(x)|| --> infinity} is non-empty and nowhere dense in X. Moreover, if…

Functional Analysis · Mathematics 2022-06-14 Petr Hajek , Richard J. Smith

The classification of gradings by abelian groups on finite direct sums of simple finite-dimensional nonassociative algebras over an algebraically closed field is reduced, by means of the use of loop algebras, to the corresponding problem…

Rings and Algebras · Mathematics 2019-04-25 Alejandra S. Córdova-Martínez , Alberto Elduque

This paper is concerned with derivations in algebras of (unbounded) operators affiliated with a von Neumann algebra $\mathcal{M}$. Let $\mathcal{% A}$ be one of the algebras of measurable operators, locally measurable operators or, $\tau…

Operator Algebras · Mathematics 2009-07-08 A. F. Ber , B. de Pagter , F. A. Sukochev

Remarks are given to the structure of physical states in 2D gravity coupled to $C\leq 1$ matter. The operator algebra of the discrete state operators is calculated for the theory with non-vanishing cosmological constant.

High Energy Physics - Theory · Physics 2011-04-15 Vl. S. Dotsenko

In this article, we compute both the algebraic and the analytic Brauer groups of a homogeneous space under the action of a connected, simply connected, semisimple complex algebraic group, where the stabilizer subgroup is closed and…

Algebraic Geometry · Mathematics 2026-05-22 Saurav Bhaumik , Pinakinath Saha

Let $n\in\mathbb{N}$ and let $A$ be a closed linear operator (everywhere bounded or unbounded). In this paper, we study (among others) equations of the type $A^*A=A^n$ where $n\geq2$ and see when they yield $A=A^*$ (or a weaker class of…

Functional Analysis · Mathematics 2019-02-07 Souheyb Dehimi , Mohammed Hichem Mortad , Zsigmond Tarcsay

Group equivariant non-expansive operators have been recently proposed as basic components in topological data analysis and deep learning. In this paper we study some geometric properties of the spaces of group equivariant operators and show…

Differential Geometry · Mathematics 2024-01-02 Pasquale Cascarano , Patrizio Frosini , Nicola Quercioli , Amir Saki

A higher rank numerical semigroup is a positive cone whose seminormalization is isomorphic to the free abelian semigroup. The corresponding nonselfadjoint semigroup algebras are known to provide examples that answer Arveson's Dilation…

Operator Algebras · Mathematics 2020-03-17 Evgenios T. A. Kakariadis , Elias G. Katsoulis , Xin Li

Let $G=K\ltimes A$ be the semi-direct product group of a compact group $K$ acting on an abelian locally compact group $A$. We describe the $C^*$-algebra $C^*(G)$ of $G$ in terms of an algebra of operator fields defined over the spectrum of…

Operator Algebras · Mathematics 2019-04-23 Hedi Regeiba , Jean Ludwig

We study the representation theory of the infinite type A Hecke algebra over a non-archimedean field in the case where the parameter is a pseudo-uniformizer. Specifically, we consider a family of representations, called almost-symmetric,…

Representation Theory · Mathematics 2026-03-25 Milo Bechtloff Weising

We provide an operator algebraic interpretation of discrete measurable groupoids in the course of re-proving (and slightly generalizing) a result on treeability due to Adams and Spatzier. Then, we reconstruct Gaboriau's beautiful work on…

Operator Algebras · Mathematics 2019-05-21 Yoshimichi Ueda

Recently M.E. Shirokov introduced the non-commutative operator graph depending on the complex parameter $\theta $ to construct channels with positive quantum zero-error capacity having vanishing n-shot capacity. We study the algebraic…

Quantum Physics · Physics 2016-06-01 Grigori G. Amosov , I. Yu. Zhdanovskiy

We describe the multiplier algebra of the noncommutative Schwartz space. This multiplier algebra can be seen as the largest ${}^*$-algebra of unbounded operators on a separable Hilbert space with the classical Schwartz space of rapidly…

Functional Analysis · Mathematics 2021-03-10 Tomasz Ciaś , Krzysztof Piszczek

In [LV] the authors defined a Hecke algebra action and a bar involution on a vector space spanned by the involutions in a Weyl group. In this paper we give a new definition of the Hecke algebra action and the bar operator which, unlike the…

Representation Theory · Mathematics 2012-01-04 G. Lusztig

We expand on some invariants used for classifying nonselfadjoint operator algebras. Specifically to nonselfadjoint operator algebras which have a conditional expectation onto a commutative diagonal we construct an edge-colored directed…

Operator Algebras · Mathematics 2013-07-23 Benton Duncan

For some time now, conformal field theories in two dimensions have been studied as integrable systems. Much of the success of these studies is related to the existence of an operator algebra of the theory. In this paper, some of the…

High Energy Physics - Theory · Physics 2009-11-11 Jasbir Nagi

We propose a new definition for a Banach algebra $\mathfrak{A}$ to be extremely non-Arens regular, namely that the quotient $\mathfrak{A}^\ast/\mathscr{WAP}(\mathfrak{A})$ of $\mathfrak{A}^\ast$ with the space of its weakly almost periodic…

Functional Analysis · Mathematics 2020-06-02 Mahmoud Filali , Jorge Galindo

We study infinite matrices $A$ indexed by a discrete group $G$ that are dominated by a convolution operator in the sense that $|(Ac)(x)| \leq (a \ast |c|)(x)$ for $x\in G$ and some $a\in \ell ^1(G)$. This class of "convolution-dominated"…

Functional Analysis · Mathematics 2010-12-21 Gero Fendler , Karlheinz Gröchenig , Michael Leinert

We look at classes of semiassociative algebras, with an emphasis on those that canonically generalize associative (generalized) cyclic algebras, and at their behaviour in the semiassociative Brauer monoid defined by Blachar, Haile, Matzri,…

Rings and Algebras · Mathematics 2024-07-15 S Pumpluen