{ "id": "2109.01536", "version": "v1", "published": "2021-09-03T14:01:02.000Z", "updated": "2021-09-03T14:01:02.000Z", "title": "Extremal problems of double stars", "authors": [ "Ervin Győri", "Runze Wang", "Spencer Woolfson" ], "comment": "19 pages, 4 figures", "categories": [ "math.CO" ], "abstract": "In a generalized Tur\\'an problem, two graphs $H$ and $F$ are given and the question is the maximum number of copies of $H$ in an $F$-free graph of order $n$. In this paper, we study the number of double stars $S_{k,l}$ in triangle-free graphs. We also study an opposite version of this question: what is the maximum number edges/triangles in graphs with double star type restrictions, which leads us to study two questions related to the extremal number of triangles or edges in graphs with degree-sum constraints over adjacent or non-adjacent vertices.", "revisions": [ { "version": "v1", "updated": "2021-09-03T14:01:02.000Z" } ], "analyses": { "subjects": [ "05C35" ], "keywords": [ "extremal problems", "maximum number edges/triangles", "double star type restrictions", "non-adjacent vertices", "generalized turan problem" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }