English

Hitting times in the stochastic block model

Probability 2024-02-16 v1 Combinatorics

Abstract

Given a large connected graph G=(V,E)G=(V,E), and two vertices w,vw,\neq v, let Tw,vT_{w,v} be the first hitting time to vv starting from ww for the simple random walk on GG. We prove a general theorem that guarantees, under some assumptions on GG, to approximate E[Tw,v]\mathbb E[T_{w,v}] up to o(1)o(1) terms. As a corollary, we derive explicit formulas for the stochastic block model with two communities and connectivity parameters pp and qq, and show that the average hitting times, for fixed vv and as ww varies, concentrates around four possible values. The proof is purely probabilistic and uses a coupling argument.

Keywords

Cite

@article{arxiv.2402.09624,
  title  = {Hitting times in the stochastic block model},
  author = {Andrea Ottolini},
  journal= {arXiv preprint arXiv:2402.09624},
  year   = {2024}
}

Comments

2 figures

R2 v1 2026-06-28T14:49:06.660Z