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Related papers: The Operator System Generated by Cuntz Isometries

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We initiate the study of the small scale geometry of operator spaces. The authors have previously shown that a map between operator spaces which is completely coarse (that is, the sequence of its amplifications is equi-coarse) must be…

Operator Algebras · Mathematics 2024-05-01 Bruno de Mendonça Braga , Javier Alejandro Chávez-Domínguez

We study the spectrum of operators in the Schwartz space of rapidly decreasing functions which associate each function with its composition with a polynomial. In the case where this operator is mean ergodic we prove that its spectrum…

Functional Analysis · Mathematics 2018-11-01 Carmen Fernández , Antonio Galbis , Enrique Jordá

We construct geometrically the generating fields of a W algebra which acts irreducibly on the direct sum of the cohomology rings of the Hilbert schemes of n points on a projective surface for all n. We compute explicitly the commutators…

Algebraic Geometry · Mathematics 2007-05-23 Wei-Ping Li , Zhenbo Qin , Weiqiang Wang

In this article, we give an abstract characterization of the ``identity'' of an operator space $V$ by looking at a quantity $n_{cb}(V,u)$ which is defined in analogue to a well-known quantity in Banach space theory. More precisely, we show…

Operator Algebras · Mathematics 2008-05-27 Xu-Jian Huang , Chi-Keung Ng

Certain $*$-semigroups are associated with the universal $C^*$-algebra generated by a partial isometry, which is itself the universal $C^*$-algebra of a $*$-semigroup. A fundamental role for a $*$-structure on a semigroup is emphasized, and…

Operator Algebras · Mathematics 2014-06-03 Berndt Brenken

We specify the structure of completely positive operators and quantum Markov semigroup generators that are symmetric with respect to a family of inner products, also providing new information on the order strucure an extreme points in some…

Functional Analysis · Mathematics 2020-09-15 Érik Amorim , Eric A. Carlen

Let $K$ be any unital commutative $\mathbb Q$-algebra and $z=(z_1, ..., z_n)$ commutative or noncommutative free variables. Let $t$ be a formal parameter which commutes with $z$ and elements of $K$. We denote uniformly by $\kzz$ and…

Combinatorics · Mathematics 2007-10-30 Wenhua Zhao

Permutative automorphisms of the Cuntz algebras $\mathcal{O}_n$ are in bijection with the stable permutations of $[n]^t$. They are also the elements of the reduced Weyl group of $Aut(\mathcal{O}_n)$. In this paper, we characterize the…

Operator Algebras · Mathematics 2025-07-25 Junyao Pan

The extension problem asks whether positive semi-definite functions on a symmetric unital subset of a discrete group can be extended to positive semi-definite functions on the whole group. It has been known at least since the work of Rudin…

Operator Algebras · Mathematics 2026-04-01 Evgenios T. A. Kakariadis , Malte Leimbach , Ivan G. Todorov , Walter D. van Suijlekom

In this paper, we show how a class of operators used in the analysis of measures from wavelets and iterated function systems may be understood from a special family of representations of Cuntz algebras.

Operator Algebras · Mathematics 2007-05-23 Palle E. T. Jorgensen

A quasi-Hermitian operator is an operator that is similar to its adjoint in some sense, via a metric operator, i.e., a strictly positive self-adjoint operator. Whereas those metric operators are in general assumed to be bounded, we analyze…

Mathematical Physics · Physics 2014-09-12 Jean-Pierre Antoine , Camillo Trapani

Given a bounded domain in the Euclidean space satisfying the uniform outer cone condition, we show that a uniformly elliptic operator of second order with continuous second order coefficients generates a holomorphic semigroup on the space…

Analysis of PDEs · Mathematics 2010-10-11 Wolfgang Arendt , Reiner Schätzle

Some of the operator product expansions (OPEs) between the lowest 16 higher spin currents of spins (1, 3/2, 3/2, 3/2, 3/2, 2, 2, 2, 2, 2, 2, 5/2, 5/2, 5/2, 5/2, 3) in an extension of the large N=4 linear superconformal algebra were…

High Energy Physics - Theory · Physics 2016-08-03 Changhyun Ahn , Man Hea Kim

We define and analyze Toeplitz operators whose symbols are the elements of the complex quantum plane, a non-commutative, infinite dimensional algebra. In particular, the symbols do not come from an algebra of functions. The process of…

Mathematical Physics · Physics 2013-05-31 Stephen Bruce Sontz

An operator *-algebra is a non-selfadjoint operator algebra with completely isometric involution. We show that any operator *-algebra admits a faithful representation on a Hilbert space in such a way that the involution coincides with the…

Operator Algebras · Mathematics 2019-11-28 David Blecher , Jens Kaad , Bram Mesland

We give a new definition for the crossed-product of a C*-algebra A by a *-endomorphism \alpha, which depends not only on the pair (A,\alpha) but also on the choice of a transfer operator (defined in the paper). With this we generalize some…

Operator Algebras · Mathematics 2007-05-23 Ruy Exel

In this paper we characterize the isometries of subspaces of the little Zygmund space. We show that the isometries of these spaces are surjective and represented as integral operators. We also show that all hermitian operators on these…

Functional Analysis · Mathematics 2019-08-15 Fernanda Botelho

We give a construction of an odd spectral triple on the Cuntz algebra $O_{N}$, whose $K$-homology class generates the odd $K$-homology group $K^1(O_{N})$. Using a metric measure space structure on the Cuntz-Renault groupoid, we introduce a…

Operator Algebras · Mathematics 2018-08-17 Magnus Goffeng , Bram Mesland

This paper addresses the isomorphism problem for the universal (nonself-adjoint) operator algebras generated by a row contraction subject to homogeneous polynomial relations. We find that two such algebras are isometrically isomorphic if…

Operator Algebras · Mathematics 2011-07-15 Kenneth R. Davidson , Christopher Ramsey , Orr Shalit

We define co-Toeplitz operators, a new class of Hilbert space operators, in order to define a co-Toeplitz quantization scheme that is dual to the Toeplitz quantization scheme introduced by the author in the setting of symbols that come from…

Mathematical Physics · Physics 2019-12-09 Stephen Bruce Sontz