Jordan homomorphisms and T-ideals
Abstract
Let and be associative algebras over a field with {\rm char}. Our first main result states that if is unital and equal to its commutator ideal, then every Jordan epimorphism is the sum of a homomorphism and an antihomomorphism. Our second main result concerns (not necessarily surjective) Jordan homomorphisms from to , where is an involution on and . We show that there exists a -ideal having the following two properties: (1) the Jordan homomorphism can be extended to an (associative) homomorphism, subject to the condition that the subalgebra generated by has trivial annihilator, and (2) every element of the -ideal of identities of the algebra of matrices is nilpotent modulo . A similar statement is true for Jordan homomorphisms from to . A counter-example shows that the assumption on trivial annihilator cannot be removed.
Keywords
Cite
@article{arxiv.2508.07191,
title = {Jordan homomorphisms and T-ideals},
author = {Matej Brešar and Efim Zelmanov},
journal= {arXiv preprint arXiv:2508.07191},
year = {2025}
}