Thresholds for contagious sets in random graphs

Fuente: arXiv
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Main Authors: Angel, Omer, Kolesnik, Brett
Format: Preprint
Published: 2016
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author Angel, Omer
Kolesnik, Brett
author_facet Angel, Omer
Kolesnik, Brett
contents For fixed $r\geq 2$, we consider bootstrap percolation with threshold $r$ on the Erdős-Rényi graph ${\cal G}_{n,p}$. We identify a threshold for $p$ above which there is with high probability a set of size $r$ which can infect the entire graph. This improves a result of Feige, Krivelevich and Reichman, which gives bounds for this threshold, up to multiplicative constants. As an application of our results, we also obtain an upper bound for the threshold for $K_4$-bootstrap percolation on ${\cal G}_{n,p}$, as studied by Balogh, Bollobás and Morris. We conjecture that our bound is asymptotically sharp. These thresholds are closely related to the survival probabilities of certain time-varying branching processes, and we derive asymptotic formulae for these survival probabilities which are of interest in their own right.
format Preprint
id arxiv_https___arxiv_org_abs_1611_10167
institution arXiv
publishDate 2016
record_format arxiv
spellingShingle Thresholds for contagious sets in random graphs
Angel, Omer
Kolesnik, Brett
Probability
Combinatorics
05C80, 60K35, 37B15, 60J85, 82B26
For fixed $r\geq 2$, we consider bootstrap percolation with threshold $r$ on the Erdős-Rényi graph ${\cal G}_{n,p}$. We identify a threshold for $p$ above which there is with high probability a set of size $r$ which can infect the entire graph. This improves a result of Feige, Krivelevich and Reichman, which gives bounds for this threshold, up to multiplicative constants. As an application of our results, we also obtain an upper bound for the threshold for $K_4$-bootstrap percolation on ${\cal G}_{n,p}$, as studied by Balogh, Bollobás and Morris. We conjecture that our bound is asymptotically sharp. These thresholds are closely related to the survival probabilities of certain time-varying branching processes, and we derive asymptotic formulae for these survival probabilities which are of interest in their own right.
title Thresholds for contagious sets in random graphs
topic Probability
Combinatorics
05C80, 60K35, 37B15, 60J85, 82B26
url https://arxiv.org/abs/1611.10167