{ "id": "1803.03240", "version": "v1", "published": "2018-03-08T18:27:32.000Z", "updated": "2018-03-08T18:27:32.000Z", "title": "The maximum number of $P_\\ell$ copies in $P_k$-free graphs", "authors": [ "Ervin Győri", "Nika Salia", "Casey Tompkins", "Oscar Zamora" ], "categories": [ "math.CO" ], "abstract": "Generalizing Tur\\'an's classical extremal problem, Alon and Shikhelman investigated the problem of maximizing the number of $T$ copies in an $H$-free graph, for a pair of graphs $T$ and $H$. Whereas Alon and Shikhelman were primarily interested in determining the order of magnitude for large classes of graphs $H$, we focus on the case when $T$ and $H$ are paths, where we find asymptotic and in some cases exact results. We also consider other structures like stars and the set of cycles of length at least $k$, where we derive asymptotically sharp estimates. Our results generalize well-known extremal theorems of Erd\\H{o}s and Gallai.", "revisions": [ { "version": "v1", "updated": "2018-03-08T18:27:32.000Z" } ], "analyses": { "keywords": [ "free graph", "maximum number", "results generalize well-known extremal theorems", "cases exact results", "generalizing turans classical extremal problem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }