{ "id": "1312.1213", "version": "v1", "published": "2013-12-04T15:43:26.000Z", "updated": "2013-12-04T15:43:26.000Z", "title": "Forcing $k$-repetitions in degree sequences", "authors": [ "Yair Caro", "Asaf Shapira", "Raphael Yuster" ], "categories": [ "math.CO" ], "abstract": "One of the most basic results in graph theory states that every graph with at least two vertices has two vertices with the same degree. Since there are graphs without $3$ vertices of the same degree, it is natural to ask if for any fixed $k$, every graph $G$ is ``close'' to a graph $G'$ with $k$ vertices of the same degree. Our main result in this paper is that this is indeed the case. Specifically, we show that for any positive integer $k$, there is a constant $C=C(k)$, so that given any graph $G$, one can remove from $G$ at most $C$ vertices and thus obtain a new graph $G'$ that contains at least $\\min\\{k,|G|-C\\}$ vertices of the same degree. Our main tool is a multidimensional zero-sum theorem for integer sequences, which we prove using an old geometric approach of Alon and Berman.", "revisions": [ { "version": "v1", "updated": "2013-12-04T15:43:26.000Z" } ], "analyses": { "subjects": [ "05C07" ], "keywords": [ "degree sequences", "repetitions", "graph theory states", "multidimensional zero-sum theorem", "old geometric approach" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1312.1213C" } } }