Block factorization of the relative entropy via spatial mixing
arXiv:2004.10574 · doi:10.1007/s00220-021-04237-1
Abstract
We consider spin systems in the -dimensional lattice satisfying the so-called strong spatial mixing condition. We show that the relative entropy functional of the corresponding Gibbs measure satisfies a family of inequalities which control the entropy on a given region in terms of a weighted sum of the entropies on blocks when each is given an arbitrary nonnegative weight . These inequalities generalize the well known logarithmic Sobolev inequality for the Glauber dynamics. Moreover, they provide a natural extension of the classical Shearer inequality satisfied by the Shannon entropy. Finally, they imply a family of modified logarithmic Sobolev inequalities which give quantitative control on the convergence to equilibrium of arbitrary weighted block dynamics of heat bath type.
23 pages, 2 figures