Hyper-regular graphs and high dimensional expanders
Abstract
Let be a finite graph. For we say that is -regular, if every has degree . We say that is -regular, for , if is regular and for every , the subgraph induced on 's neighbors is -regular. Similarly, is -regular for , if is regular and for every , the joint neighborhood of every clique of size is -regular; In that case, we say that is an -dimensional hyper-regular graph (HRG). Here we define a new kind of graph product, through which we build examples of infinite families of -dimensional HRG such that the joint neighborhood of every clique of size at most is connected. In particular, relying on the work of Kaufman and Oppenheim, our product yields an infinite family of -dimensional HRG for arbitrarily large with good expansion properties. This answers a question of Dinur regarding the existence of such objects.
Cite
@article{arxiv.2010.03829,
title = {Hyper-regular graphs and high dimensional expanders},
author = {Ehud Friedgut and Yonatan Iluz},
journal= {arXiv preprint arXiv:2010.03829},
year = {2023}
}
Comments
27 pages