Aldous' spectral gap phenomena in stochastic exchange models
This paper establishes that for a broad class of conservative continuous-spin exchange models, the spectral gap is always determined by a polynomial of degree at most two (corresponding to one- or two-particle observables), thereby resolving a conjecture by Alon and Puder and characterizing how the dominance of one- versus two-particle modes depends on the underlying geometry, while also showing that boundary-driven variants of these systems always exhibit a one-particle spectral gap.