{ "id": "2011.07612", "version": "v1", "published": "2020-11-15T19:36:42.000Z", "updated": "2020-11-15T19:36:42.000Z", "title": "Triangles in randomly perturbed graphs", "authors": [ "Julia Böttcher", "Olaf Parczyk", "Amedeo Sgueglia", "Jozef Skokan" ], "comment": "30 pages, 1 figure", "categories": [ "math.CO" ], "abstract": "We study the problem of finding pairwise vertex-disjoint triangles in the randomly perturbed graph model, which is the union of any $n$-vertex graph $G$ with linear minimum degree and the binomial random graph $G(n,p)$. We prove that asymptotically almost surely $G \\cup G(n,p)$ contains $\\min \\{\\delta(G), \\lfloor n/3 \\rfloor \\}$ pairwise vertex-disjoint triangles, provided $p \\ge C \\log n/n$, where $C$ is a large enough constant. This is a perturbed version of an old result of Dirac. Our result is asymptotically optimal and answers a question of Han, Morris, and Treglown [RSA, to appear] in the case of triangle-factors. Together with a result of Balogh, Treglown, and Wagner [CPC, 2019, no. 2, 159-176] this fully resolves the existence of triangle-factors in randomly perturbed graphs. We also prove a stability version of our result. Finally, we discuss further generalisations to larger clique-factors, larger cycle-factors, and $2$-universality.", "revisions": [ { "version": "v1", "updated": "2020-11-15T19:36:42.000Z" } ], "analyses": { "keywords": [ "binomial random graph", "linear minimum degree", "vertex graph", "finding pairwise vertex-disjoint triangles", "randomly perturbed graph model" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable" } } }