English

Normal group algebras

Rings and Algebras 2019-02-27 v1

Abstract

Let FG\mathbb{F}G denote the group algebra of the group GG over the field F\mathbb{F} with char(F)2char(\mathbb{F})\neq 2. Given both a homomorphism σ:G{±1}\sigma:G\rightarrow \{\pm1\} and a group involution :GG\ast: G\rightarrow G, an oriented involution of FG\mathbb{F}G is defined by α=Σαggα=Σαgσ(g)g\alpha=\Sigma\alpha_{g}g \mapsto \alpha^\circledast=\Sigma\alpha_{g}\sigma(g)g^{\ast}. In this paper, we determine the conditions under which the group algebra FG\mathbb{F}G is normal, that is, conditions under which FG\mathbb{F}G satisfies the \circledast-identity αα=αα\alpha\alpha^\circledast=\alpha^\circledast\alpha. We prove that FG\mathbb{F}G is normal if and only if the set of symmetric elements under \circledast is commutative.

Keywords

Cite

@article{arxiv.1902.09620,
  title  = {Normal group algebras},
  author = {Alexander Holguín-Villa and John H. Castillo},
  journal= {arXiv preprint arXiv:1902.09620},
  year   = {2019}
}

Comments

12 pages

R2 v1 2026-06-23T07:50:53.299Z