{ "id": "2202.02301", "version": "v1", "published": "2022-02-04T18:37:37.000Z", "updated": "2022-02-04T18:37:37.000Z", "title": "Log-Sobolev inequality for near critical Ising models", "authors": [ "Roland Bauerschmidt", "Benoit Dagallier" ], "categories": [ "math.PR", "math-ph", "math.MP" ], "abstract": "For general ferromagnetic Ising models whose coupling matrix has bounded spectral radius, we show that the log-Sobolev constant satisfies a simple bound expressed only in terms of the susceptibility of the model. This bound implies very generally that the log-Sobolev constant is uniform in the system size up to the critical point (including on lattices), without using any mixing conditions. Moreover, if the susceptibility satisfies the mean-field bound as the critical point is approached, our bound implies that the log-Sobolev constant depends polynomially on the distance to the critical point and on the volume. In particular, this applies to the Ising model on subsets of $\\mathbb{Z}^d$ when $d>4$. The proof uses a general criterion for the log-Sobolev inequality in terms of the Polchinski (renormalisation group) equation, a recently proved remarkable correlation inequality for Ising models with general external fields, the Perron--Frobenius theorem, and the log-Sobolev inequality for product Bernoulli measures.", "revisions": [ { "version": "v1", "updated": "2022-02-04T18:37:37.000Z" } ], "analyses": { "keywords": [ "log-sobolev inequality", "critical ising models", "critical point", "bound implies", "product bernoulli measures" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }