English

An ${\mathfrak S}_3$-cover of $K_4$ and integral polyhedral graphs

Combinatorics 2026-02-06 v2

Abstract

We show that the star graph defined as the Cayley graph of Sn+1{\mathfrak S}_{n+1} generated by the star transpositions is an Sn{\mathfrak S}_n-cover of the complete graph Kn+1K_{n+1}, which is known to have fine spectral properties. In the case n=3n = 3, the star graph also has fine geometric properties: it embeds into the honeycomb lattice and has a spectrum computable via both representation theory and an explicit Fourier formula. Intermediate covers correspond to the cube and truncated tetrahedron, offering a new interpretation of their integral spectra.

Keywords

Cite

@article{arxiv.2508.18593,
  title  = {An ${\mathfrak S}_3$-cover of $K_4$ and integral polyhedral graphs},
  author = {Taizo Sadahiro},
  journal= {arXiv preprint arXiv:2508.18593},
  year   = {2026}
}