English

Graphs with few trivial characteristic ideals

Combinatorics 2020-04-02 v1

Abstract

We give a characterization of the graphs with at most three trivial characteristic ideals. This implies the complete characterization of the regular graphs whose critical groups have at most three invariant factors equal to 1 and the characterization of the graphs whose Smith groups have at most 3 invariant factors equal to 1. We also give an alternative and simpler way to obtain the characterization of the graphs whose Smith groups have at most 3 invariant factors equal to 1, and a list of minimal forbidden graphs for the family of graphs with Smith group having at most 4 invariant factors equal to 1.

Keywords

Cite

@article{arxiv.2004.00172,
  title  = {Graphs with few trivial characteristic ideals},
  author = {Carlos A. Alfaro and Michael D. Barrus and John Sinkovic and Ralihe R. Villagrán},
  journal= {arXiv preprint arXiv:2004.00172},
  year   = {2020}
}

Comments

21 pages

R2 v1 2026-06-23T14:34:41.492Z