Barak-Erdős graphs and the infinite-bin model
arXiv:1610.04043 · doi:10.1214/20-AIHP1141
Abstract
A Barak-Erdős graph is a directed acyclic version of the Erdős-Rényi random graph. It is obtained by performing independent bond percolation with parameter on the complete graph with vertices , in which the edge between two vertices is directed from to . The length of the longest path in this graph grows linearly with the number of vertices, at rate . In this article, we use a coupling between Barak-Erdős graphs and infinite-bin models to provide explicit estimates on . More precisely, we prove that the front of an infinite-bin model grows at linear speed, and that this speed can be obtained as the sum of a series. Using these results, we prove the analyticity of for , and compute its power series expansion. We also obtain the first two terms of the asymptotic expansion of as , using a coupling with branching random walks.
36 pages, 5 figures