Multiplicative and Jordan multiplicative maps on structural matrix algebras

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Gogić, Ilja, Tomašević, Mateo
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918217697460224
author Gogić, Ilja
Tomašević, Mateo
author_facet Gogić, Ilja
Tomašević, Mateo
contents Let $M_n$ denote the algebra of $n \times n$ complex matrices and let $\mathcal{A}\subseteq M_n$ be an arbitrary structural matrix algebra, i.e. a subalgebra of $M_n$ that contains all diagonal matrices. We consider injective maps $ϕ: \mathcal{A}\to M_n$ that satisfy the condition $$ ϕ(X \bullet Y) = ϕ(X) \bullet ϕ(Y), \quad \text{for all } X,Y \in \mathcal{A}, $$ where $\bullet$ is either the standard matrix multiplication $(X,Y)\mapsto XY$, the Jordan product $(X,Y) \mapsto XY+YX$, or the normalized Jordan product $(X,Y) \mapsto \frac{1}{2}(XY+YX)$. We show that all such maps $ϕ$ are automatically additive if and only if $\mathcal{A}$ does not contain a central rank-one idempotent. Moreover, in this case, we fully characterize the form of these maps.
format Preprint
id arxiv_https___arxiv_org_abs_2503_14116
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Multiplicative and Jordan multiplicative maps on structural matrix algebras
Gogić, Ilja
Tomašević, Mateo
Rings and Algebras
47B49, 16S50, 16W20, 20M25
Let $M_n$ denote the algebra of $n \times n$ complex matrices and let $\mathcal{A}\subseteq M_n$ be an arbitrary structural matrix algebra, i.e. a subalgebra of $M_n$ that contains all diagonal matrices. We consider injective maps $ϕ: \mathcal{A}\to M_n$ that satisfy the condition $$ ϕ(X \bullet Y) = ϕ(X) \bullet ϕ(Y), \quad \text{for all } X,Y \in \mathcal{A}, $$ where $\bullet$ is either the standard matrix multiplication $(X,Y)\mapsto XY$, the Jordan product $(X,Y) \mapsto XY+YX$, or the normalized Jordan product $(X,Y) \mapsto \frac{1}{2}(XY+YX)$. We show that all such maps $ϕ$ are automatically additive if and only if $\mathcal{A}$ does not contain a central rank-one idempotent. Moreover, in this case, we fully characterize the form of these maps.
title Multiplicative and Jordan multiplicative maps on structural matrix algebras
topic Rings and Algebras
47B49, 16S50, 16W20, 20M25
url https://arxiv.org/abs/2503.14116