{ "id": "math/0605397", "version": "v2", "published": "2006-05-15T15:40:50.000Z", "updated": "2015-06-22T15:05:28.000Z", "title": "An explicit bound on the Logarithmic Sobolev constant of weakly dependent random variables", "authors": [ "Katalin Marton" ], "comment": "This paper has been withdrawn by the author because it was a preliminary version of arXiv:1206.4868", "categories": [ "math.PR", "math-ph", "math.MP" ], "abstract": "We prove logarithmic Sobolev inequality for measures $$ q^n(x^n)=\\text{dist}(X^n)=\\exp\\bigl(-V(x^n)\\bigr), \\quad x^n\\in \\Bbb R^n, $$ under the assumptions that: (i) the conditional distributions $$ Q_i(\\cdot| x_j, j\\neq i)=\\text{dist}(X_i| X_j= x_j, j\\neq i) $$ satisfy a logarithmic Sobolev inequality with a common constant $\\rho$, and (ii) they also satisfy some condition expressing that the mixed partial derivatives of the Hamiltonian $V$ are not too large relative to $\\rho$. \\bigskip Condition (ii) has the form that the norms of some matrices defined in terms of the mixed partial derivatives of $V$ do not exceed $1/2\\cdot\\rho\\cdot(1-\\de)$. The logarithmic Sobolev constant of $q^n$ can then be estimated from below by $1/2\\cdot\\rho\\cdot\\delta$. This improves on earlier results by Th. Bodineau and B. Helffer, by giving an explicit bound, for the logarithmic Sobolev constant for $q^n$.", "revisions": [ { "version": "v1", "updated": "2006-05-15T15:40:50.000Z", "comment": "31 pages", "journal": null, "doi": null }, { "version": "v2", "updated": "2015-06-22T15:05:28.000Z" } ], "analyses": { "keywords": [ "logarithmic sobolev constant", "weakly dependent random variables", "explicit bound", "logarithmic sobolev inequality", "mixed partial derivatives" ], "note": { "typesetting": "TeX", "pages": 31, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......5397M" } } }