{ "id": "1202.5351", "version": "v5", "published": "2012-02-24T00:47:02.000Z", "updated": "2015-01-23T11:13:50.000Z", "title": "Bootstrap percolation on the Hamming torus", "authors": [ "Janko Gravner", "Christopher Hoffman", "James Pfeiffer", "David Sivakoff" ], "comment": "Published in at http://dx.doi.org/10.1214/13-AAP996 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)", "journal": "Annals of Applied Probability 2015, Vol. 25, No. 1, 287-323", "doi": "10.1214/13-AAP996", "categories": [ "math.PR" ], "abstract": "The Hamming torus of dimension $d$ is the graph with vertices $\\{1,\\dots,n\\}^d$ and an edge between any two vertices that differ in a single coordinate. Bootstrap percolation with threshold $\\theta$ starts with a random set of open vertices, to which every vertex belongs independently with probability $p$, and at each time step the open set grows by adjoining every vertex with at least $\\theta$ open neighbors. We assume that $n$ is large and that $p$ scales as $n^{-\\alpha}$ for some $\\alpha>1$, and study the probability that an $i$-dimensional subgraph ever becomes open. For large $\\theta$, we prove that the critical exponent $\\alpha$ is about $1+d/\\theta$ for $i=1$, and about $1+2/\\theta+\\Theta(\\theta^{-3/2})$ for $i\\ge2$. Our small $\\theta$ results are mostly limited to $d=3$, where we identify the critical $\\alpha$ in many cases and, when $\\theta=3$, compute exactly the critical probability that the entire graph is eventually open.", "revisions": [ { "version": "v4", "updated": "2013-11-19T20:36:08.000Z", "title": "Bootstrap Percolation on the Hamming Torus", "abstract": "The Hamming torus of dimension $d$ is the graph with vertices ${1,..., n}^d$ and an edge between any two vertices that differ in a single coordinate. Bootstrap percolation with threshold $\\theta$ starts with a random set of open vertices, to which every vertex belongs independently with probability $p$, and at each time step the open set grows by adjoining every vertex with at least $\\theta$ open neighbors. We assume that $n$ is large and that $p$ scales as $n^{-\\alpha}$ for some $\\alpha>1$, and study the probability that an $i$-dimensional subgraph ever becomes open. For large $\\theta$, we prove that the critical exponent $\\alpha$ is about $1+d/\\theta$ for $i=1$, and about $1+2/\\theta+\\Theta(\\theta^{-3/2})$ for $i\\ge 2$. Our small $\\theta$ results are mostly limited to $d=3$, where we identify the critical $\\alpha$ in many cases and, when $\\theta=3$, compute exactly the critical probability that the entire graph is eventually open.", "comment": null, "journal": null, "doi": null }, { "version": "v5", "updated": "2015-01-23T11:13:50.000Z" } ], "analyses": { "keywords": [ "bootstrap percolation", "hamming torus", "probability", "open set grows", "open vertices" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }