Critical density of activated random walks on transitive graphs

Alexandre Stauffer, Lorenzo Taggi

Research output: Contribution to journalArticlepeer-review

12 Citations (SciVal)
34 Downloads (Pure)


We consider the activated random walk model on general vertextransitive graphs. A central question in this model is whether the critical density μ c for sustained activity is strictly between 0 and 1. It was known that μ c > 0 on Z d, d = 1, and that μ c < 1 on Z for small enough sleeping rate. We show that μ c → 0 as λ → 0 in all vertex-transitive transient graphs, implying that μ c < 1 for small enough sleeping rate. We also show that μ c < 1 for any sleeping rate in any vertex-transitive graph in which simple random walk has positive speed. Furthermore, we prove that μc > 0 in any vertex-transitive amenable graph, and that μ c ∞ (0, 1) for any sleeping rate on regular trees.

Original languageEnglish
Pages (from-to)2190-2220
Number of pages31
JournalAnnals of Probability
Issue number4
Early online date30 Jun 2018
Publication statusPublished - 31 Jul 2018


  • Absorbing states phase transitions
  • Interacting particle systems
  • Random walks

ASJC Scopus subject areas

  • Statistics and Probability
  • Statistics, Probability and Uncertainty


Dive into the research topics of 'Critical density of activated random walks on transitive graphs'. Together they form a unique fingerprint.

Cite this