{ "id": "2003.13139", "version": "v1", "published": "2020-03-29T21:04:59.000Z", "updated": "2020-03-29T21:04:59.000Z", "title": "The 1-2-3 Conjecture holds for graphs with large enough minimum degree", "authors": [ "Jakub PrzybyƂo" ], "comment": "21 pages", "categories": [ "math.CO" ], "abstract": "A simple graph more often than not contains adjacent vertices with equal degrees. This in particular holds for all pairs of neighbours in regular graphs, while a lot such pairs can be expected e.g. in many random models. Is there a universal constant $K$, say $K=3$, such that one may always dispose of such pairs from any given connected graph with at least three vertices by blowing its selected edges into at most $K$ parallel edges? This question was first posed in 2004 by Karo\\'nski, {\\L}uczak and Thomason, who equivalently asked if one may assign weights $1,2,3$ to the edges of every such graph so that adjacent vertices receive distinct weighted degrees - the sums of their incident weights. This basic problem is commonly referred to as the 1-2-3 Conjecture nowadays, and has been addressed in multiple papers. Thus far it is known that weights $1,2,3,4,5$ are sufficient [J. Combin. Theory Ser. B 100 (2010) 347-349]. We show that this conjecture holds if only the minimum degree $\\delta$ of a graph is large enough, i.e. when $\\delta = \\Omega(\\log\\Delta)$, where $\\Delta$ denotes the maximum degree of the graph. The principle idea behind our probabilistic proof relies on associating random variables with a special and carefully designed distribution to most of the vertices of a given graph, and then choosing weights for major part of the edges depending on the values of these variables in a deterministic or random manner.", "revisions": [ { "version": "v1", "updated": "2020-03-29T21:04:59.000Z" } ], "analyses": { "subjects": [ "05C15", "05C78" ], "keywords": [ "conjecture holds", "minimum degree", "contains adjacent vertices", "vertices receive distinct weighted degrees", "adjacent vertices receive distinct" ], "note": { "typesetting": "TeX", "pages": 21, "language": "en", "license": "arXiv", "status": "editable" } } }