{ "id": "1010.3326", "version": "v2", "published": "2010-10-16T06:22:53.000Z", "updated": "2011-02-24T03:12:16.000Z", "title": "The sharp threshold for bootstrap percolation in all dimensions", "authors": [ "József Balogh", "Béla Bollobás", "Hugo Duminil-Copin", "Robert Morris" ], "comment": "37 pages, sketch of the proof added, to appear in Trans. of the AMS", "categories": [ "math.PR", "math-ph", "math.CO", "math.DS", "math.MP" ], "abstract": "In r-neighbour bootstrap percolation on a graph G, a (typically random) set A of initially 'infected' vertices spreads by infecting (at each time step) vertices with at least r already-infected neighbours. This process may be viewed as a monotone version of the Glauber dynamics of the Ising model, and has been extensively studied on the d-dimensional grid $[n]^d$. The elements of the set A are usually chosen independently, with some density p, and the main question is to determine $p_c([n]^d,r)$, the density at which percolation (infection of the entire vertex set) becomes likely. In this paper we prove, for every pair $d \\ge r \\ge 2$, that there is a constant L(d,r) such that $p_c([n]^d,r) = [(L(d,r) + o(1)) / log_(r-1) (n)]^{d-r+1}$ as $n \\to \\infty$, where $log_r$ denotes an r-times iterated logarithm. We thus prove the existence of a sharp threshold for percolation in any (fixed) number of dimensions. Moreover, we determine L(d,r) for every pair (d,r).", "revisions": [ { "version": "v2", "updated": "2011-02-24T03:12:16.000Z" } ], "analyses": { "subjects": [ "60K35", "60C05" ], "keywords": [ "sharp threshold", "dimensions", "r-neighbour bootstrap percolation", "entire vertex set", "vertices spreads" ], "note": { "typesetting": "TeX", "pages": 37, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1010.3326B" } } }