Signatures, lifts, and eigenvalues of graphs [article]

Shiping Liu, Norbert Peyerimhoff, Alina Vdovina
2014 arXiv   pre-print
We study the spectra of cyclic signatures of finite graphs and the corresponding cyclic lifts. Starting from a bipartite Ramanujan graph, we prove the existence of an infinite tower of 3-cyclic lifts, each of which is again Ramanujan.
arXiv:1412.6841v1 fatcat:r4ttbitf7jhqvisunv33jntgaa