{ "id": "0911.4741", "version": "v1", "published": "2009-11-24T23:52:18.000Z", "updated": "2009-11-24T23:52:18.000Z", "title": "The spectrum of random k-lifts of large graphs (with possibly large k)", "authors": [ "Roberto Imbuzeiro Oliveira" ], "journal": "Journal of Combinatorics 1 (3/4) p.285-306, 2011", "categories": [ "math.CO", "math.PR" ], "abstract": "We study random k-lifts of large, but otherwise arbitrary graphs G. We prove that, with high probability, all eigenvalues of the adjacency matrix of the lift that are not eigenvalues of G are of the order (D ln (kn))^{1/2}, where D is the maximum degree of G. Similarly, and also with high probability, the \"new\" eigenvalues of the Laplacian of the lift are all in an interval of length (ln (nk)/d)^{1/2} around 1, where d is the minimum degree of G. We also prove that, from the point of view of Spectral Graph Theory, there is very little difference between a random k_1k_2 ... k_r-lift of a graph and a random k_1-lift of a random k_2-lift of ... of a random k_r-lift of the same graph. The main proof tool is a concentration inequality for sums of random matrices that was recently introduced by the author.", "revisions": [ { "version": "v1", "updated": "2009-11-24T23:52:18.000Z" } ], "analyses": { "keywords": [ "large graphs", "possibly large", "high probability", "eigenvalues", "spectral graph theory" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0911.4741I" } } }