Mixing times of random walks on dynamic configuration models

Citation
Avena, Luca et al., Mixing times of random walks on dynamic configuration models, Annals of applied probability , 28(4), 2018, pp. 1977-2002
ISSN journal
10505164
Volume
28
Issue
4
Year of publication
2018
Pages
1977 - 2002
Database
ACNP
SICI code
Abstract
The mixing time of a random walk, with or without backtracking, on a random graph generated according to the configuration model on n vertices, is known to be of order logn. In this paper, we investigate what happens when the random graph becomes dynamic, namely, at each unit of time a fraction .n of the edges is randomly rewired. Under mild conditions on the degree sequence, guaranteeing that the graph is locally tree-like, we show that for every ..(0,1) the .-mixing time of random walk without backtracking grows like .2log(1/.)/log(1/(1..n)) as n.., provided that limn...n(logn)2=.. The latter condition corresponds to a regime of fast enough graph dynamics. Our proof is based on a randomised stopping time argument, in combination with coupling techniques and combinatorial estimates. The stopping time of interest is the first time that the walk moves along an edge that was rewired before, which turns out to be close to a strong stationary time.