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Related papers: Operator System Nuclearity via $C^*$-envelopes

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Description of a nuclear system in its ground state and at low excitations based on the equation of state (EoS) around normal density is presented. In the expansion of the EoS around the saturation point additional spin polarization terms…

We study the local operator space structure of nuclear $C^*$-algebras. It is shown that a $C^*$-algebra is nuclear if and only if it is an $\OL_{\infty, \la}$ space for some (and actually for every) $\la > 6$. The $\OL_\infty$ constant…

Operator Algebras · Mathematics 2007-05-23 M. Junge , N. Ozawa , Z. J. Ruan

In the setting of product systems over group-embeddable monoids, we consider nuclearity of the associated Toeplitz C*-algebra in relation to nuclearity of the coefficient algebra. Our work goes beyond the known cases of single…

Operator Algebras · Mathematics 2025-08-27 Elias G. Katsoulis , Marcelo Laca , Camila F. Sehnem

We study subproduct systems in the sense of Shalit and Solel arising from stochastic matrices on countable state spaces, and their associated operator algebras. We focus on the non-self-adjoint tensor algebra, and Viselter's generalization…

Operator Algebras · Mathematics 2016-11-18 Adam Dor-On , Daniel Markiewicz

Consider any sequence of finite groups $A^t$, where $t$ takes values in an integer index set $\mathbf{Z}$. A group system $A$ is a set of sequences with components in $A^t$ that forms a group under componentwise addition in $A^t$, for each…

Information Theory · Computer Science 2022-08-16 Kenneth M. Mackenthun

The study of open quantum systems relies on the notion of unital completely positive semigroups on $C^*$-algebras representing physical systems. The natural generalisation would be to consider the unital completely positive semigroups on…

Operator Algebras · Mathematics 2022-11-15 V. I. Yashin

We study the issue of issue of purity (as a completely positive linear map) for identity maps on operators systems and for their completely isometric embeddings into their C$^*$-envelopes and injective envelopes. Our most general result…

Operator Algebras · Mathematics 2020-06-16 Douglas Farenick , Ryan Tessier

Let $\sS$ be a countable, abelian semigroup of continuous surjections on a compact metric space $X$. Corresponding to this dynamical system we associate two operator algebras, the tensor algebra, and the semicrossed product. There is a…

Operator Algebras · Mathematics 2014-10-07 Benton L. Duncan , Justin R. Peters

Let $H_1,H_2$ be complex Hilbert spaces and $T$ be a densely defined closed linear operator (not necessarily bounded). It is proved that for each $\epsilon>0$, there exists a bounded operator $S$ with $\|S\|\leq \epsilon$ such that $T+S$ is…

Functional Analysis · Mathematics 2016-09-23 S. H. Kulkarni , G. Ramesh

We construct a family of operator systems and $k$-AOU spaces generated by a finite number of projections satisfying a set of linear relations. This family is universal in the sense that the map sending the generating projections to any…

Operator Algebras · Mathematics 2025-12-03 Roy Araiza , Travis Russell

Nuclearity plays an important role for the Schwartz kernel theorem to hold and in transferring the surjectivity of a linear partial differential operator from scalar-valued to vector-valued functions via tensor product theory. In this paper…

Functional Analysis · Mathematics 2021-04-08 Karsten Kruse

For Ore semigroups $P$ with an order unit, we prove that there is a bijection between $E_0$-semigroups over $P$ and product systems of $C^{*}$-correspondences over $P^{op}$. We exploit this bijection and show that the reduced…

Operator Algebras · Mathematics 2025-07-29 Md Amir Hossain , S. Sundar

We will give an abstract characterization of an arbitrary self-adjoint weak$^*$-closed subspace of $\mathcal{L}(H)$ (equipped with the induced matrix norm, the induced matrix cone and the induced weak$^*$-topology). In order to do this, we…

Functional Analysis · Mathematics 2022-06-10 Yu-Shu Jia , Chi-Keung Ng

We investigate closure operators and describe their properties for $E$-combinations and $P$-combinations of structures and their theories. We prove, for $E$-combinations, that the existence of a minimal generating set of theories is…

Logic · Mathematics 2016-01-05 Sergey V. Sudoplatov

Operator systems are the unital self-adjoint subspaces of the bounded operators on a Hilbert space. Complex operator systems are an important category containing the C*-algebras and von Neumann algebras, which is increasingly of interest in…

Operator Algebras · Mathematics 2025-10-07 David P. Blecher , Travis B. Russell

We prove a quantized version of a theorem by M. V. Sheinberg: A uniform algebra equipped with its canonical, i.e. minimal, operator space structure is operator amenable if and only if it is a commutative $C^\ast$-algebra.

Functional Analysis · Mathematics 2007-05-23 Volker Runde

A notion of super operator system is defined which generalizes the usual notion of operator systems to include certain unital involutive operator spaces which cannot be represented completely isometric as a concrete operator system on some…

Operator Algebras · Mathematics 2013-08-05 Ulrich Haag

We give an alternative construction of the essential $C^*$-algebra of an \'etale groupoid, along with an ``amenability'' notion for such groupoids that is implied by the nuclearity of this essential $C^*$-algebra. In order to do this we…

Operator Algebras · Mathematics 2025-04-18 Alcides Buss , Diego Martínez

In this contribution we extend the concept of a Petri net morphism to Elementary Object Systems (EOS). EOS are a nets-within-nets formalism, i.e. we allow the tokens of a Petri net to be Petri nets again. This nested structure has the…

Logic in Computer Science · Computer Science 2024-11-04 Michael Köhler-Bussmeier , Lorenzo Capra

We will investigate the norm closure of the unitary and similarity orbits of normal operators in unital, simple, purely infinite C*-algebras. An operator theoretic proof will be given to the classification of when two normal operators are…

Operator Algebras · Mathematics 2013-05-28 Paul Skoufranis