Cutoffs for exclusion and interchange processes on finite graphs

Abstract

We prove a general theorem on cutoffs for symmetric exclusion and interchange processes on finite graphs $G_N=(V_N,E_N)$, under the assumption that either the graphs converge geometrically and spectrally to a compact metric measure space, or they are isomorphic to discrete Boolean hypercubes. Specifically, cutoffs occur at times $\displaystyle t_N= (2\gamma_1^N)^{-1}\log |V_N|$, where $\gamma_1^N$ is the spectral gap of the symmetric random walk process on $G_N$. Under the former assumption, our theorem is applicable to the said processes on graphs such as: the $d$-dimensional discrete grids and tori for any integer dimension $d$; the $L$-th powers of cycles for fixed $L$, a.k.a. the $L$-adjacent transposition shuffle; and self-similar fractal graphs and products thereof.