On the Spread of Random Graphs
2014 (English)In: Combinatorics, probability & computing, ISSN 0963-5483, E-ISSN 1469-2163, Vol. 23, no 4, 477-504 p.Article in journal (Refereed) Published
The spread of a connected graph G was introduced by Alon, Boppana and Spencer , and measures how tightly connected the graph is. It is defined as the maximum over all Lipschitz functions f on V(G) of the variance of f(X) when X is uniformly distributed on V(G). We investigate the spread for certain models of sparse random graph, in particular for random regular graphs G(n,d), for Erdos-Renyi random graphs G(n,p) in the supercritical range p > 1/n, and for a `small world' model. For supercritical G(n,p), we show that if p = c/n with c > 1 fixed, then with high probability the spread of the giant component is bounded, and we prove corresponding statements for other models of random graphs, including a model with random edge lengths. We also give lower bounds on the spread for the barely supercritical case when p = (1 + o(1))/n. Further, we show that for d large, with high probability the spread of G(n, d) becomes arbitrarily close to that of the complete graph K-n.
Place, publisher, year, edition, pages
2014. Vol. 23, no 4, 477-504 p.
IdentifiersURN: urn:nbn:se:uu:diva-229429DOI: 10.1017/S0963548314000248ISI: 000338350900001OAI: oai:DiVA.org:uu-229429DiVA: diva2:736795