2004/01/08 by Christian Borgs, Borgs, Christian, Jennifer T. Chayes +7 · 1 citation
Mathematics · #05C80 #60K35 #82B43 #Combinatorics (math.CO) #FOS: Mathematics #Probability (math.PR) #math.CO #math.PR #msc:05C80 #msc:60K35 #msc:82B43
paper · pdf · doi:10.48550/arxiv.math/0401071
14 pages
arxiv created 2004/01/08 · arxiv updated 2009/12/01
We study random subgraphs of the n-cube \0,1\n, where nearest-neighbor edges are occupied with probability p. Let pc(n) be the value of p for which the expected cluster size of a fixed vertex attains the value λ2n/3, where λ is a small positive constant. Let ε=n(p-pc(n)). In two previous papers, we showed that the largest cluster inside a scaling window given by |ε|=Θ(2-n/3) is of size Θ(22n/3), below this scaling window it is at most 2(log2) nε-2, and above this scaling window it is at most O(ε2n). In this paper, we prove that for p - pc(n) ≥ e^-cn1/3 the size of the largest cluster is at least Θ(ε2n), which is of the same order as the upper bound. This provides an understanding of the phase transition that goes far beyond that obtained by previous authors. The proof is based on a method that has come to be known as ``sprinkling,'' and relies heavily on the specific geometry of the n-cube.