English

Centrally Stable Algebras

Rings and Algebras 2020-01-01 v2

Abstract

We define an algebra AA to be centrally stable if, for every epimorhism φ\varphi from AA to another algebra BB, the center Z(B)Z(B) of BB is equal to φ(Z(A))\varphi(Z(A)), the image of the center of AA. After providing some examples and basic observations, we consider in somewhat greater detail central stability in tensor products of algebras, and finally establish our main result which states that a finite-dimensional unital algebra AA over a perfect field FF is centrally stable if and only if AA is isomorphic to a direct product of algebras of the form CiFiAiC_i\otimes_{F_i}A_i, where FiF_i is a field extension of FF, CiC_i is a commutative FiF_i-algebra, and AiA_i is a central simple FiF_i-algebra.

Keywords

Cite

@article{arxiv.1905.01463,
  title  = {Centrally Stable Algebras},
  author = {Matej Brešar and Ilja Gogić},
  journal= {arXiv preprint arXiv:1905.01463},
  year   = {2020}
}

Comments

15 pages, to appear in J. of Algebra

R2 v1 2026-06-23T08:56:55.049Z