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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

We derive Paschke's GNS construction for completely positive maps on unital pro-C*-algebras from the KSGNS construction, presented by M. Joita [J. London Math. Soc. {\bf 66} (2002), 421--432], and then we deduce an analogue of Stinespring…

Operator Algebras · Mathematics 2017-01-05 Khadijeh Karimi , Kamran Sharifi

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

The aim of this article is to extend the results of Asadi M.B, B.V.R. Bhat, G. Ramesh, K. Sumesh about completely positive maps on Hilbert C*-modules. We prove a Stinespring type theorem for a finite family of completely positive maps on…

Operator Algebras · Mathematics 2012-10-23 Marat Pliev

052<p type="texpara" tag="Body Text" et="abstract" >A completely $n$ -positive linear map from a locally $C^{\ast}$-algebra $A$ to another locally $C^{\ast}$-algebra $B $is an $n\times n$ matrix whose elements are continuous linear maps…

Operator Algebras · Mathematics 2007-05-23 Maria Joita

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

The order relation on the set of completely n-positive linear maps from a pro-C*-algebra A to L(H), the C*-algebra of bounded linear operators on a Hilbert space H, is characterized in terms of the representation associated with each…

Operator Algebras · Mathematics 2007-05-23 Maria Joita

We strengthen Mohammad B. Asadi's analogue of Stinespring's theorem for certain maps on Hilbert C*-modules. We also show that any two minimal Stinespring representations are unitarily equivalent. We illustrate the main theorem with an…

Operator Algebras · Mathematics 2014-05-16 B V Rajarama Bhat , G. Ramesh , K. Sumesh

We show that an operator valued $\alpha$-completely positive map on a group G is given by a unitary representation of G on a Krein space which satisfies some condition. Moreover, two unitary equivalent such unitary representations define…

Operator Algebras · Mathematics 2013-08-08 Maria Joiţa

The notion of completely positive invariant conjugate-bilinear map in a partial *-algebra is introduced and a generalized Stinespring theorem is proven. Applications to the existence of integrable extensions of *-representations of…

Mathematical Physics · Physics 2009-04-07 F. Bagarello , A. Inoue , C. Trapani

We introduce a preorder relation in the collection of all operator valued completely positive maps on a full Hilbert C*-module and characterize this relation in terms of the Stinespring construction associated to each completely positive…

Operator Algebras · Mathematics 2018-06-18 Maria Joiţa

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

In this paper, we investigate $\Phi$-maps associated to a certain type of $\alpha$-completely positive maps. We then prove a KSGNS (Kasparov--Stinespring--Gel'fand--Naimark--Segal) type theorem for $\alpha $-completely positive maps on…

Operator Algebras · Mathematics 2021-07-23 Mohammad Sal Moslehian , Maria Joita , Un Cig Ji

A very general KSGNS type dilation theorem in the context of right (not necessarily Hilbert) modules over $C^*$-algebras is presented. The proof uses Kolmogorov type decompositions for positive-definite kernels with values in spaces of…

Operator Algebras · Mathematics 2011-09-14 Juha-Pekka Pellonpää , Kari Ylinen

We prove a covariant version of the KSGNS (Kasparov, Stinespring, Gel'fand,Naimark,Segal) construction for completely positive linear maps between locally $C^{*}$-algebras. As an application of this construction, we show that a covariant…

Operator Algebras · Mathematics 2007-05-23 Maria Joita

The aim of this note is to establish two Radon--Nikodym type theorems for nonnegative Hermitian forms defined on a real or complex vector space. We apply these results to prove the known Radon--Nikodym theorems of the theory of…

Functional Analysis · Mathematics 2014-04-18 Zsigmond Tarcsay

Motivated by Cuntz-Krieger-Toeplitz systems associated to undirected graphs and representations of groupoids, we obtain a generalisation of the Sz-Nagy's Dilation Theorem for operator valued partially positive semidefinite maps on…

Operator Algebras · Mathematics 2025-11-04 Aurelian Gheondea , Bogdan Udrea

We give a constructive elementary proof for the fact that any K-automorphism of the full nxn matrix algebra over a field K is conjugation by some invertible nxn matrix A over K.

Rings and Algebras · Mathematics 2018-10-22 Jeno Szigeti , Leon van Wyk

We introduce S-modules, generalizing the notion of Krein $C^*$-modules, where a fixed unitary replaces the symmetry of Krein $C^*$-modules. The representation theory on S-modules is explored and for a given $*$-automorphism $\alpha$ on a…

Operator Algebras · Mathematics 2018-06-12 Santanu Dey , Harsh Trivedi

In this article, we investigate certain basic properties of invariant multilinear CP maps. For instance, we prove Russo-Dye type theorem for invariant multilinear positive maps on both commutative $C^*$-algebras and finite-dimensional…

Operator Algebras · Mathematics 2024-01-10 Anindya Ghatak , Aryaman Sensarma
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