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Related papers: Relative Kubo-Ando Means of Completely Positive Ma…

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We introduce the geometric mean and the parallel sum of completely positive (CP) maps on von Neumann algebras, based on the Pusz--Woronowicz theory of positive sesquilinear forms. We provide a concrete characterization via a block matrix…

Operator Algebras · Mathematics 2026-05-08 Rui Okayasu

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

In this paper, we establish a bijection between Kubo-Ando operator means defined on the cones $\mathscr{P}_{n}(\mathbb{H})$, $\mathscr{P}_{2n}(\mathbb{C})$, and $\mathscr{P}_{4n}(\mathbb{R})$. This correspondence is induced by the canonical…

Functional Analysis · Mathematics 2026-05-28 Jose Franco , Allan Merino

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

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

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

In this paper, we introduce the concept of completely positive matrix of linear maps on Hilbert $A$-modules over locally $C^{*}$-algebras and prove an analogue of Stinespring theorem for it. We show that any two minimal Stinespring…

Operator Algebras · Mathematics 2021-07-23 M. S. Moslehian , A. Kusraev , M. Pliev

We investigate the stability of quantum positivity cones under nonlinear operator means. Specifically, we examine how Kubo--Ando means interact with the separable, positive partial transpose (PPT), and Schmidt-number cones. By analyzing the…

Quantum Physics · Physics 2026-05-27 Mohsen Kian

In this paper, we discuss positive maps induced by (irreducibly) covariant linear operators for finite groups. The application of group theory methods allows deriving some new results of a different kind. In particular, a family of…

Quantum Physics · Physics 2020-09-07 Piotr Kopszak , Marek Mozrzymas , Michał Studziński

Given a completely positive (CP) map $T$, there is a theorem of the Radon-Nikodym type [W.B. Arveson, Acta Math. {\bf 123}, 141 (1969); V.P. Belavkin and P. Staszewski, Rep. Math. Phys. {\bf 24}, 49 (1986)] that completely characterizes all…

Mathematical Physics · Physics 2007-05-23 Maxim Raginsky

We provide a complete characterization of a subclass of weakly associative means of positive operators in the class of symmetric Kubo-Ando means. This class, which includes the geometric mean, was first introduced and studied in L.…

Functional Analysis · Mathematics 2025-02-19 Yury Grabovsky , Graeme W. Milton , Aaron Welters

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

The generalization of the geometric mean of positive scalars to positive definite matrices has attracted considerable attention since the seminal work of Ando. The paper generalizes this framework of matrix means by proposing the definition…

Optimization and Control · Mathematics 2013-04-12 Silvere Bonnabel , Anne Collard , Rodolphe Sepulchre

We study methods of inducing metrics on unital completely positive maps by employing seminorms arising in noncommutative geometry. Our main approach relies on the development of an infinite-dimensional $C^*$-algebraic analogue of the…

Operator Algebras · Mathematics 2026-05-14 Are Austad , Erik Bédos , Jonas Eidesen , Nadia S. Larsen , Tron Omland

For positive definite matrices $A$ and $B$, the Kubo-Ando matrix power mean is defined as $$ P_\mu(p, A, B) = A^{1/2}\left(\frac{1+(A^{-1/2}BA^{-1/2})^p}{2}\right )^{1/p} A^{1/2}\quad (p \ge 0). $$ In this paper, for $0\le p \le 1 \le q$,…

Functional Analysis · Mathematics 2021-07-14 Trung Hoa Dinh , Cong Trinh Le , The Van Nguyen , Bich Khue Vo

We initiate a study of linear maps on $M_n(\mathbb{C})$ that have the property that they factor through a tracial von Neumann algebra $(\mathcal{A,\tau})$ via operators $Z\in M_n(\mathcal{A})$ whose entries consist of positive elements from…

Operator Algebras · Mathematics 2021-09-06 Jeremy Levick , Mizanur Rahaman

In this article we consider means of positive operators on a Hilbert space. We extend the theory of matrix power means to arbitrary operator means in the sense of Kubo-Ando. The basis of the extension is relying on ideas coming from…

Functional Analysis · Mathematics 2013-03-22 Miklós Pálfia

We present natural conjectural generalizations of the `positivity and integrality of mirror maps' phenomenon, encompassing the mirror maps appearing in the Batyrev--Borisov construction of mirror Calabi--Yau complete intersections in Fano…

Number Theory · Mathematics 2026-03-27 Sophie Bleau , Nick Sheridan

We present a general characterization of k-positivity for a positive map in terms of the estimation of the Ky Fan norm of the matrix constructed from the Kraus operators of the associated completely positive map. Combining this with the…

Quantum Physics · Physics 2024-08-13 Marcin Marciniak , Tomasz Młynik , Hiroyuki Osaka
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