van Dam, E.R.; Haemers, W.H.; Koolen, J.H. - Tilburg University, School of Economics and Management - 2014
We study the energy per vertex in regular graphs. For every k⩾2, we give an upper bound for the energy per vertex of a k -regular graph, and show that a graph attains the upper bound if and only if it is the disjoint union of incidence graphs of projective planes of order k−1 or, in case...
