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Let $T:E\rightarrow F$ be a non-necessarily continuous triple homomorphism from a (complex) JB$^*$-triple (respectively, a (real) J$^*$B-triple) to a normed Jordan triple. The following statements hold: (1) $T$ has closed range whenever $T$…

Operator Algebras · Mathematics 2024-02-02 Francisco J. Fernández-Polo , Jorge J. Garcés , Antonio M. Peralta

We prove that a unital completely positive map between finite-dimensional C*-algebras is a homomorphism if and only if it is completely entropy-nonincreasing, where the relevant notion of entropy is a variant of von Neumann entropy. This…

Operator Algebras · Mathematics 2025-01-22 Andre Kornell

The aim of this paper is to characterize those linear maps from a von Neumann factor $\A$ into itself which preserve the extreme points of the unit ball of $\A$. For example, we show that if $\A$ is infinite, then every such linear…

Functional Analysis · Mathematics 2016-09-07 Vania Mascioni , Lajos Molnar

We introduce the concept of finitely coloured equivalence for unital *-homomorphisms between C*-algebras, for which unitary equivalence is the 1-coloured case. We use this notion to classify *-homomorphisms from separable, unital, nuclear…

Operator Algebras · Mathematics 2019-04-24 Joan Bosa , Nathanial P. Brown , Yasuhiko Sato , Aaron Tikuisis , Stuart White , Wilhelm Winter

In this paper, we investigate *-homomorphisms between C*-algebras associated to \'etale groupoids. First, we prove that such a *-homomorphism can be described by closed invariant subsets, groupoid homomorphisms and cocycles under some…

Operator Algebras · Mathematics 2023-08-24 Fuyuta Komura

We introduce a notion of approximate orthogonality preserving mappings between Hilbert $C^*$-modules. We define the concept of $(\delta, \varepsilon)$-orthogonality preserving mapping and give some sufficient conditions for a linear mapping…

Operator Algebras · Mathematics 2016-11-28 Mohammad Sal Moslehian , Ali Zamani

We study pointwise-generalized-inverses of linear maps between C$^*$-algebras. Let $\Phi$ and $\Psi$ be linear maps between complex Banach algebras $A$ and $B$. We say that $\Psi$ is a pointwise-generalized-inverse of $\Phi$ if…

Operator Algebras · Mathematics 2017-03-31 Ahlem Ben Ali Essaleh , Antonio M. Peralta , María Isabel Ramírez

Due to the corresponding fact concerning Hilbert spaces, it is natural to ask if the linearity and the orthogonality structure of a Hilbert $C^*$-module determine its $C^*$-algebra-valued inner product. We verify this in the case when the…

Operator Algebras · Mathematics 2010-05-26 Chi-Wai Leung , Chi-Keung Ng , Ngai-Ching Wong

A linear map $\phi:{\mathcal A}\to {\mathcal B} $ between (Banach) algebras is called 3-homomorphism if $\phi(abc)=\phi(a)\phi(b)\phi(c)$ for each $a, b, c \in {\mathcal A}$. We investigate 3-homomorphisms on Banach algebras with bounded…

Functional Analysis · Mathematics 2021-07-23 Janko Bracic , Mohammad Sal Moslehian

We show that for every "locally finite" unit-preserving completely positive map P acting on a C*-algebra, there is a corresponding *-automorphism \alpha of another unital C*-algebra such that the two sequences P, P^2,P^3,... and \alpha,…

Operator Algebras · Mathematics 2007-05-23 William Arveson

Every positive multilinear map between $C^*$-algebras is separately weak$^*$-continuous. We show that the joint weak$^*$-continuity is equivalent to the joint weak$^*$-continuity of the multiplications of $C^*$-algebras under consideration.…

Operator Algebras · Mathematics 2024-05-09 Ali Dadkha , Mohsen Kian , Mohammad Sal Moslehian

We prove some stability results for certain classes of C*-algebras. We prove that whenever $A$ is a finite-dimensional C*-algebra, $B$ is a C*-algebra and $\phi\colon A\to B$ is approximately a $^*$-homomorphism then there is an actual…

Operator Algebras · Mathematics 2016-07-04 Paul McKenney , Alessandro Vignati

Let $M$ and $N$ be arbitrary von Neumann algebras. For any $a$ in $M$ or in $N$, let $\Delta_{\lambda}(a)$ denote the $\lambda$-Aluthge transform of $a$. Suppose that $M$ has no abelian direct summand. We prove that every bijective map…

Operator Algebras · Mathematics 2017-12-25 Ahlem Ben Ali Essaleh , Antonio M. Peralta

Jordan operator algebras are norm-closed spaces of operators on a Hilbert space with $a^2 \in A$ for all $a \in A$. We study noncommutative topology, noncommutative peak sets and peak interpolation, and hereditary subalgebras of Jordan…

Operator Algebras · Mathematics 2018-07-05 David P. Blecher , Matthew Neal

In this paper we characterize those linear bijective maps on the monoid of all $n \times n$ square matrices over an anti-negative semifield which preserve and strongly preserve each of Green's equivalence relations $\mathcal{L},…

Rings and Algebras · Mathematics 2017-09-18 Alexander Guterman , Marianne Johnson , Mark Kambites

We prove that every biorthogonality preserving linear surjection from a weakly compact JB$^*$triple containing no infinite dimensional rank-one summands onto another JB$^*$-triple is automatically continuous. We also show that every…

Operator Algebras · Mathematics 2024-02-02 María Burgos , Jorge J. Garcés , Antonio M. Peralta

Let $D, \Omega_1, ..., \Omega_m$ be irreducible bounded symmetric domains. We study local holomorphic maps from $D$ into $\Omega_1 \times... \Omega_m$ preserving the invariant $(p, p)$-forms induced from the normalized Bergman metrics up to…

Complex Variables · Mathematics 2015-03-03 Yuan Yuan

In this article, we study the permanence of topological and algebraic dimension type properties of simple unital $C\sp*$-algebras. When a pair of unital $C\sp*$-algebras $(A, B)$ is associated by a $*$-homomorphism $\phi: A\to B$ which is…

Operator Algebras · Mathematics 2026-03-10 Hyun Ho Lee

We study morphisms of the generalized quantum logic of tripotents in JBW*-triples and von Neumann algebras. Especially, we establish generalization of celebrated Dye's theorem on orthoisomorphisms between von Neumann lattices to this new…

Operator Algebras · Mathematics 2021-01-22 Jan Hamhalter

In this paper, we investigate Jordan *-homomorphisms on $C^*$-algebras associated with the following functional inequality $\|f(\frac{b-a}{3})+f(\frac{a-3c}{3})+f(\frac{3a+3c-b}{3})\| \leq \|f(a)\|.$ We moreover prove the superstability and…

Operator Algebras · Mathematics 2008-12-17 M. Eshaghi Gordji , N. Ghobadipour , C. Park