{ "id": "2012.01664", "version": "v1", "published": "2020-12-03T02:34:50.000Z", "updated": "2020-12-03T02:34:50.000Z", "title": "The diameter of the minimum spanning tree of the complete graph with inhomogeneous random weights", "authors": [ "Othmane Safsafi" ], "comment": "30 pages, 6 figures", "categories": [ "math.PR" ], "abstract": "We study a new type of random minimum spanning trees. It is built on the complete graph where each vertex is given a weight, which is a positive real number. Then, each edge is given a capacity which is a random variable that only depends on the product of the weights of its endpoints. We then study the minimum spanning tree corresponding to the edge capacities. Under a condition of finite moments on the node weights, we show that the expected diameter and typical distances of this minimum spanning tree are of order $n^{1/3}$. This is a generalization of the results of Addario-Berry, Broutin, and Reed [2009]. We then use our result to answer a conjecture in statistical physics about typical distances on a closely related object. This work also sets the ground for proving the existence of a non-trivial scaling limit of this spanning tree (a generalization of the result of Addario-Berry, Broutin, Goldschmidt, and Miermont [2017])). Our proof is based on a detailed study of rank-1 critical inhomogeneous random graphs, done in Safsafi [2020], and novel couplings between exploration trees related to those graphs and Galton-Watson trees.", "revisions": [ { "version": "v1", "updated": "2020-12-03T02:34:50.000Z" } ], "analyses": { "subjects": [ "60C05", "05C80", "90B15" ], "keywords": [ "inhomogeneous random weights", "complete graph", "random minimum spanning trees", "typical distances", "exploration trees" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable" } } }