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Related papers: Principles of operator algebras

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We study reflexivity and structure properties of operator algebras generated by representations of the discrete Heisenberg semi-group. We show that the left regular representation of this semi-group gives rise to a semi-simple reflexive…

Operator Algebras · Mathematics 2014-07-15 M. Anoussis , A. Katavolos , I. G. Todorov

The starting points for this paper are simple descriptions of the norm and strong* closures of the unitary orbit of a normal operator in a von Neumann algebra. The statements are in terms of spectral data and do not depend on the type or…

Operator Algebras · Mathematics 2007-05-23 David Sherman

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

Jordan operator algebras are norm-closed spaces of operators on a Hilbert space with a^2 in A for all a in A. In two recent papers by the authors and Neal, a theory for these spaces was developed. It was shown there that much of the theory…

Operator Algebras · Mathematics 2018-12-27 David P. Blecher , Zhenhua Wang

Jordan operator algebras are norm-closed spaces of operators on a Hilbert space which are closed under the Jordan product. The discovery of the present paper is that there exists a huge and tractable theory of possibly nonselfadjoint Jordan…

Operator Algebras · Mathematics 2017-12-20 David P. Blecher , Zhenhua Wang

Let $\mathfrak{M}$ be a semifinite von Neumann algebra on a Hilbert space equipped with a faithful normal semifinite trace $\tau$. A closed densely defined operator $x$ affiliated with $\mathfrak{M}$ is called $\tau$-measurable if there…

Operator Algebras · Mathematics 2014-05-13 M. S. Moslehian , Gh. Sadeghi

It is shown that the differential geometry of space-time, can be expressed in terms of the algebra of operators on a bundle of Hilbert spaces. The price for this is that the algebra of smooth functions on space-time has to be made…

Mathematical Physics · Physics 2013-01-08 Michał Eckstein , Michael Heller , Leszek Pysiak , Wiesław Sasin

We consider C*-algebras associated with stable and unstable equivalence in hyperbolic dynamical systems known as Smale spaces. These systems include shifts of finite type, in which case these C*-algebras are both AF-algebras. These algebras…

Dynamical Systems · Mathematics 2012-08-27 D. Brady Killough , Ian F. Putnam

The aim of this article is to describe a class of *-algebras that allows to treat well-behaved algebras of unbounded operators independently of a representation. To this end, Archimedean ordered *-algebras (*-algebras whose real linear…

Operator Algebras · Mathematics 2021-08-20 Matthias Schötz

The set of normalizers between von Neumann (or, more generally, reflexive) algebras A and B, (that is, the set of all operators x such that xAx* is a subset of B and x*Bx is a subset of A) possesses `local linear structure': it is a union…

Operator Algebras · Mathematics 2022-06-29 A. Katavolos , I. G. Todorov

A Lax operator algebra is constructed for an arbitrary semi-simple Lie algebra over $\mathbb C$ equipped with a $\mathbb Z$-grading, and arbitrary compact Riemann surface with marked points. In this set-up, a treatment of almost graded…

Rings and Algebras · Mathematics 2020-05-11 Oleg K. Sheinman

Linear spaces with an Euclidean metric are ubiquitous in mathematics, arising both from quadratic forms and inner products. Operators on such spaces also occur naturally. In recent years, the study of multivariate operator theory has made…

Functional Analysis · Mathematics 2019-01-15 Gadadhar Misra

There has been a long-standing conjecture in Banach algebra that every amenable operator is similar to a normal operator. In this paper, we study the structure of amenable operators on Hilbert spaces. At first, we show that the conjecture…

Functional Analysis · Mathematics 2010-09-01 Luo Yi Shi , Yu Jing Wu , You Qing Ji

We suppose that $G$ is a locally compact abelian group, $Y$ is a measure space, and $H$ is a reproducing kernel Hilbert space on $G\times Y$ such that $H$ is naturally embedded into $L^2(G\times Y)$ and it is invariant under the…

Operator Algebras · Mathematics 2025-04-29 Shubham R. Bais , Egor A. Maximenko , D. Venku Naidu

The usual Laurent expansion of the analytic tensors on the complex plane is generalized to any closed and orientable Riemann surface represented as an affine algebraic curve. As an application, the operator formalism for the $b-c$ systems…

High Energy Physics - Theory · Physics 2015-06-26 F. Ferrari , J. Sobczyk

In this article, we aim to provide a satisfactory algebraic description of the set of affiliated operators for von Neumann algebras. Let $\mathscr{M}$ be a von Neumann algebra acting on a Hilbert space $\mathcal{H}$, and let…

Operator Algebras · Mathematics 2024-10-03 Indrajit Ghosh , Soumyashant Nayak

Starting from a thorough analysis of the conjugate $\overline{H}$ of a complex Hilbert space $H$, including its significant importance regarding a representation of the tensor product of two complex Hilbert spaces and its impact to the…

Quantum Physics · Physics 2026-05-18 Frank Oertel

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

Given a complex Hilbert space H, we study the differential geometry of the manifold A of normal algebraic elements in Z=L(H), the algebra of bounded linear operators on H. We represent A as a disjoint union of subsets M of Z and, using the…

Functional Analysis · Mathematics 2007-05-23 Jose M. Isidro

Every unital nonselfadjoint operator algebra possesses canonical and functorial classes of faithful (even completely isometric) Hilbert space representations satisfying a double commutant theorem generalizing von Neumann's classical result.…

Operator Algebras · Mathematics 2007-05-23 David P. Blecher , Baruch Solel