Kissing numbers of regular graphs
Combinatorics
2019-09-30 v1 Metric Geometry
Abstract
We prove a sharp upper bound on the number of shortest cycles contained inside any connected graph in terms of its number of vertices, girth, and maximal degree. Equality holds only for Moore graphs, which gives a new characterization of these graphs. In the case of regular graphs, our result improves an inequality of Teo and Koh. We also show that a subsequence of the Ramanujan graphs of Lubotzky-Phillips-Sarnak have super-linear kissing numbers.
Cite
@article{arxiv.1909.12817,
title = {Kissing numbers of regular graphs},
author = {Maxime Fortier Bourque and Bram Petri},
journal= {arXiv preprint arXiv:1909.12817},
year = {2019}
}
Comments
17 pages, 1 figure