{ "id": "1806.02903", "version": "v1", "published": "2018-06-07T21:01:54.000Z", "updated": "2018-06-07T21:01:54.000Z", "title": "A Sharp Threshold for Bootstrap Percolation in a Random Hypergraph", "authors": [ "Natasha Morrison", "Jonathan A. Noel" ], "comment": "89 pages, 14 figures", "categories": [ "math.CO", "math.PR" ], "abstract": "Given a hypergraph $\\mathcal{H}$, the $\\mathcal{H}$-bootstrap process starts with an initial set of infected vertices of $\\mathcal{H}$ and, at each step, a healthy vertex $v$ becomes infected if there exists a hyperedge of $\\mathcal{H}$ in which $v$ is the unique healthy vertex. We say that the set of initially infected vertices percolates if every vertex of $\\mathcal{H}$ is eventually infected. We show that this process exhibits a sharp threshold when $\\mathcal{H}$ is a hypergraph obtained by randomly sampling hyperedges from an approximately $d$-regular $r$-uniform hypergraph satisfying some mild degree and codegree conditions; this confirms a conjecture of Morris. As a corollary, we obtain a sharp threshold for a variant of the graph bootstrap process for strictly $2$-balanced graphs which generalises a result of Kor\\'{a}ndi, Peled and Sudakov. Our approach involves an application of the differential equations method.", "revisions": [ { "version": "v1", "updated": "2018-06-07T21:01:54.000Z" } ], "analyses": { "keywords": [ "sharp threshold", "bootstrap percolation", "random hypergraph", "unique healthy vertex", "bootstrap process starts" ], "note": { "typesetting": "TeX", "pages": 89, "language": "en", "license": "arXiv", "status": "editable" } } }