English

The $M$-matrix group inverse problem for distance-biregular graphs

Combinatorics 2022-04-29 v1

Abstract

In this paper we provide the group inverse of the combinatorial Laplacian matrix of distance-biregular graphs using the so-called equilibrium measures for sets obtained by deleting a vertex. We also show that the two equilibrium arrays characterizing a distance-biregular graph can be expressed in terms of the mentioned equilibrium measures. As a consequence of the minimum principle, we show a characterization of when the group inverse of the combinatorial Laplacian matrix of a distance-biregular graph is an MM-matrix.

Keywords

Cite

@article{arxiv.2204.13186,
  title  = {The $M$-matrix group inverse problem for distance-biregular graphs},
  author = {Aida Abiad and Ángeles Carmona and Andrés M. Encinas and María José Jiménez},
  journal= {arXiv preprint arXiv:2204.13186},
  year   = {2022}
}
R2 v1 2026-06-24T11:00:51.213Z