The spectral excess theorem for distance-biregular graphs
Combinatorics
2013-04-17 v1
Abstract
The spectral excess theorem for distance-regular graphs states that a regular (connected) graph is distance-regular if and only if its spectral-excess equals its average excess. A bipartite graph is distance-biregular when it is distance-regular around each vertex and the intersection array only depends on the stable set such a vertex belongs to. In this note we derive a new version of the spectral excess theorem for bipartite distance-biregular graphs.
Cite
@article{arxiv.1304.4354,
title = {The spectral excess theorem for distance-biregular graphs},
author = {M. A. Fiol},
journal= {arXiv preprint arXiv:1304.4354},
year = {2013}
}