{ "id": "1809.07587", "version": "v1", "published": "2018-09-20T12:16:14.000Z", "updated": "2018-09-20T12:16:14.000Z", "title": "Emergence of extended states at zero in the spectrum of sparse random graphs", "authors": [ "Simon Coste", "Justin Salez" ], "comment": "18 pages with 4 figures. Comments are welcome", "categories": [ "math.PR", "math.SP" ], "abstract": "We confirm the long-standing prediction that $c=e\\approx 2.718$ is the threshold for the emergence of a non-vanishing absolutely continuous part (extended states) at zero in the limiting spectrum of the Erd\\H{o}s-Renyi random graph with average degree $c$. This is achieved by a detailed second-order analysis of the resolvent $(A-z)^{-1}$ near the singular point $z=0$, where $A$ is the adjacency operator of the Poisson-Galton-Watson tree with mean offspring $c$. More generally, our method applies to arbitrary unimodular Galton-Watson trees, yielding explicit criteria for the presence or absence of extended states at zero in the limiting spectral measure of a variety of random graph models, in terms of the underlying degree distribution.", "revisions": [ { "version": "v1", "updated": "2018-09-20T12:16:14.000Z" } ], "analyses": { "keywords": [ "sparse random graphs", "extended states", "arbitrary unimodular galton-watson trees", "random graph models", "adjacency operator" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable" } } }