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arXiv · 2109.13849

On bipartite distance-regular Cayley graphs with small diameter

Edwin R. van Dam·Mojtaba Jazaeri
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Abstract

We study bipartite distance-regular Cayley graphs with diameter three or four. We give sufficient conditions under which a bipartite Cayley graph can be constructed on the semidirect product of a group -- the part of this bipartite Cayley graph which contains the identity element -- and $\mathbb{Z}_{2}$. We apply this to the case of bipartite distance-regular Cayley graphs with diameter three, and consider cases where the sufficient conditions are not satisfied for some specific groups such as the dihedral group. We also extend a result by Miklavi\v{c} and Poto\v{c}nik that relates difference sets to bipartite distance-regular Cayley graphs with diameter three to the case of diameter four. This new case involves certain partial geometric difference sets and -- in the antipodal case -- relative difference sets.

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Edwin R. van Dam, Mojtaba Jazaeri. 2021-09-28. On bipartite distance-regular Cayley graphs with small diameter. https://arxiv.org/abs/2109.13849

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