{ "id": "2305.08442", "version": "v1", "published": "2023-05-15T08:40:16.000Z", "updated": "2023-05-15T08:40:16.000Z", "title": "Crowns in pseudo-random graphs and Hamilton cycles in their squares", "authors": [ "Michael Krivelevich" ], "categories": [ "math.CO" ], "abstract": "A crown with $k$ spikes is an edge-disjoint union of a cycle $C$ and a matching $M$ of size $k$ such that each edge of $M$ has exactly one vertex in common with $C$. We prove that if $G$ is an $(n,d,\\lambda)$-graph with $\\lambda/d\\le 0.001$ and $d$ is large enough, then $G$ contains a crown on $n$ vertices with $\\lfloor n/2\\rfloor$ spikes. As a consequence, such $G$ contains a Hamilton cycle in its square $G^2$.", "revisions": [ { "version": "v1", "updated": "2023-05-15T08:40:16.000Z" } ], "analyses": { "subjects": [ "05C80", "05C45" ], "keywords": [ "hamilton cycle", "pseudo-random graphs", "edge-disjoint union", "consequence" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }