English
Related papers

Related papers: Completely positive invariant conjugate-bilinear m…

200 papers

We prove a local convex version of Arveson's extension theorem and of Wittstock's extension theorem. Also we prove a Stinespring type theorem for unbounded local completely contractive maps.

Operator Algebras · Mathematics 2022-02-11 Maria Joiţa

A completely positive linear map $\varphi$ from a C*-algebra $A$ into $B(H)$ has a Stinespring representation as $\varphi(a) = X^*\pi(a)X,$ where $\pi$ is a *-representation of $A$ on a Hilbert space $K$ and $X$ is a bounded operator from…

Operator Algebras · Mathematics 2021-08-27 Erik Christensen

In this article, we introduce local completely positive $k$-linear maps between locally $C^{\ast}$-algebras and obtain Stinespring type representation by adopting the notion of "invariance" defined by J. Heo for $k$-linear maps between…

Operator Algebras · Mathematics 2021-10-01 Anindya Ghatak , Santhosh Kumar Pamula

Stochastic generators of completely positive and contractive quantum stochastic convolution cocycles on a C*-hyperbialgebra are characterised. The characterisation is used to obtain dilations and stochastic forms of Stinespring…

Operator Algebras · Mathematics 2009-11-11 Adam Skalski

This paper examines actions of right LCM semigroups by endomorphisms of C*-algebras that encode an additional structure of the right LCM semigroup. We define contractive covariant representations for these semigroup dynamical systems and…

Operator Algebras · Mathematics 2021-10-19 Marcelo Laca , Boyu Li

Given a pair of self-adjoint-preserving completely bounded maps on the same $C^*$-algebra, say that $\varphi \leq \psi$ if the kernel of $\varphi$ is a subset of the kernel of $\psi$ and $\psi \circ \varphi^{-1}$ is completely positive. The…

Operator Algebras · Mathematics 2022-04-07 J. E. Pascoe , Ryan Tully-Doyle

We consider positive semidefinite kernels valued in the $*$-algebra of continuous and continuously adjointable operators on a VH-space (Vector Hilbert space in the sense of Loynes) and that are invariant under actions of $*$-semigroups. For…

Operator Algebras · Mathematics 2025-11-04 Serdar Ay , Aurelian Gheondea

We introduce an equivalence relation on the set of all completely positive maps between Hilbert modules over pro-C*-algebras and analyze the Stinespring's construction for equivalent completely positive maps. We then give a preorder…

Operator Algebras · Mathematics 2025-05-21 Bhumi Amin , Ramesh Golla

Convex sets of completely positive maps and positive semidefinite kernels are considered in the most general context of modules over $C^*$-algebras and a complete charaterization of their extreme points is obtained. As a byproduct, we…

Quantum Physics · Physics 2014-03-05 Juha-Pekka Pellonpää

Anar A. Dosiev in [Local operator spaces, unbounded operators and multinormed $C^*$-algebras, J. Funct. Anal. 255 (2008), 1724-1760], obtained a Stinespring's theorem for local completely positive maps (in short: local CP-maps) on locally…

Operator Algebras · Mathematics 2021-01-05 B. V. Rajarama Bhat , Anindya Ghatak , P. Santhosh Kumar

W. Paschke's version of Stinespring's theorem associates a Hilbert $C^*$-module along with a generating vector to every completely positive map. Building on this, to every quantum dynamical semigroup (QDS) on a $C^*$-algebra $\mathcal A$…

Operator Algebras · Mathematics 2021-12-03 B V Rajarama Bhat , Vijaya Kumar U

A linear map between matrix spaces is positive if it maps positive semidefinite matrices to positive semidefinite ones, and is called completely positive if all its ampliations are positive. In this article quantitative bounds on the…

Functional Analysis · Mathematics 2019-07-10 Igor Klep , Scott McCullough , Klemen Šivic , Aljaž Zalar

In this paper, we provide a representation of a certain class of C*-valued positive sesquilinear and linear maps on non-unital quasi *-algebras. Also, we illustrate our results on the concrete examples of non-unital Banach quasi *-algebras,…

Operator Algebras · Mathematics 2024-09-10 Stefan Ivkovic , Bogdan D. Djordjevic , Giorgia Bellomonte

Inspired by the commutator and anticommutator algebras derived from algebras graded by groups, we introduce noncommutatively graded algebras. We generalize various classical graded results to the noncommutatively graded situation concerning…

Rings and Algebras · Mathematics 2017-11-01 Patrik Nystedt

The GNS construction for positive invariant sesquilinear forms on quasi *-algebras is generalized to a class of positive C*-valued sesquilinear maps on quasi *-algebras. The result is a *-representation taking values in a space of operators…

Operator Algebras · Mathematics 2024-08-08 Giorgia Bellomonte , Stefan Ivkovic , Camillo Trapani

We introduce completely semi-$\varphi$-maps on Hilbert $C^*$-modules as a generalization of $\varphi$-maps. This class of maps provides examples of CP-extendable maps which are not CP-H-extendable, in Skeide-Sumesh's sense. Using the…

Operator Algebras · Mathematics 2016-08-02 Mohammad B. Asadi , Reza Behmani , Ali R. Medghalchi , Hamed Nikpey

We give a Stinespring representation of the Schur block product, say (*), on pairs of square matrices with entries in a C*-algebra as a completely bounded bilinear operator of the form: A:=(a_{ij}), B:= (b_{ij}): A (*) B := (a_{ij}b_{ij}) =…

Operator Algebras · Mathematics 2018-11-12 Erik Christensen

Motivated by advances in categorical probability, we introduce non-commutative almost everywhere (a.e.) equivalence and disintegrations in the setting of C*-algebras. We show that C*-algebras (resp. W*-algebras) and a.e. equivalence classes…

Quantum Physics · Physics 2023-12-18 Arthur J. Parzygnat , Benjamin P. Russo

We show how the proof of the Grothendieck Theorem for jointly completely bounded bilinear forms on C*-algebras by Haagerup and Musat can be modified in such a way that the method of proof is essentially C*-algebraic. To this purpose, we use…

Operator Algebras · Mathematics 2015-12-02 Tim de Laat

We shall prove the following Stinespring-type theorem: there exists a triple $(\pi,\mathcal{H},\mathbf{V})$ associated with an unital completely positive map $\Phi:\mathfrak{A}\rightarrow \mathfrak{A}$ on C* algebra $\mathfrak{A}$ with…

Operator Algebras · Mathematics 2011-07-21 Carlo Pandiscia