English

Finite skew braces with isomorphic non-abelian characteristically simple additive and circle groups

Rings and Algebras 2022-04-05 v2 Group Theory

Abstract

A skew brace is a triplet (A,,)(A,\cdot,\circ), where (A,)(A,\cdot) and (A,)(A,\circ) are groups such that the brace relation x(yz)=(xy)x1(xz)x\circ (y\cdot z) = (x\circ y)\cdot x^{-1}\cdot (x\circ z) holds for all x,y,zAx,y,z\in A. In this paper, we study the number of finite skew braces (A,,)(A,\cdot,\circ), up to isomorphism, such that (A,)(A,\cdot) and (A,)(A,\circ) are both isomorphic to TnT^n with TT non-abelian simple and nNn\in\mathbb{N}. We prove that it is equal to the number of unlabeled directed graphs on n+1n+1 vertices, with one distingusihed vertex, and whose underlying undirected graph is a tree. In particular, it depends only on nn and is independent of TT.

Keywords

Cite

@article{arxiv.2009.00266,
  title  = {Finite skew braces with isomorphic non-abelian characteristically simple additive and circle groups},
  author = {Cindy Tsang},
  journal= {arXiv preprint arXiv:2009.00266},
  year   = {2022}
}

Comments

slightly revised based on referee's comments