English

Orientably-Regular $\pi$-Maps and Regular $\pi$-Maps

Combinatorics 2022-09-19 v1

Abstract

Given a map with underlying graph G\mathcal{G}, if the set of prime divisors of V(G|V(\mathcal{G}| is denoted by π\pi, then we call the map a {\it π\pi-map}. An orientably-regular (resp. A regular ) π\pi-map is called {\it solvable} if the group G+G^+ of all orientation-preserving automorphisms (resp. the group GG of automorphisms) is solvable; and called {\it normal} if G+G^+ (resp. GG) contains a normal π\pi-Hall subgroup. In this paper, it will be proved that orientably-regular π\pi-maps are solvable and normal if 2π2\notin \pi and regular π\pi-maps are solvable if 2π2\notin \pi and GG has no sections isomorphic to PSL(2,q){\rm PSL}(2,q) for some prime power qq. In particular, it's shown that a regular π\pi-map with 2π2\notin \pi is normal if and only if G/O2(G)G/O_{2^{'}}(G) is isomorphic to a Sylow 22-group of GG. Moreover, nonnormal π\pi-maps will be characterized and some properties and constructions of normal π\pi-maps will be given in respective sections.

Keywords

Cite

@article{arxiv.2209.07991,
  title  = {Orientably-Regular $\pi$-Maps and Regular $\pi$-Maps},
  author = {Xiaogang Li and Yao Tian},
  journal= {arXiv preprint arXiv:2209.07991},
  year   = {2022}
}

Comments

18 pages. arXiv admin note: substantial text overlap with arXiv:2201.04305

R2 v1 2026-06-28T01:27:35.810Z