{ "id": "math/0503585", "version": "v1", "published": "2005-03-25T08:58:54.000Z", "updated": "2005-03-25T08:58:54.000Z", "title": "Modified logarithmic Sobolev inequalities in null curvature", "authors": [ "Ivan Gentil", "Arnaud Guillin", "Laurent Miclo" ], "categories": [ "math.PR", "math.FA" ], "abstract": "We present a logarithmic Sobolev inequality adapted to a log-concave measure. Assume that $\\Phi$ is a symmetric convex function on $\\dR$ satisfying $(1+\\e)\\Phi(x)\\leq {x}\\Phi'(x)\\leq(2-\\e)\\Phi(x)$ for $x\\geq0$ large enough and with $\\e\\in]0,1/2]$. We prove that the probability measure on $\\dR$ $\\mu_\\Phi(dx)=e^{-\\Phi(x)}/Z_\\Phi dx$ satisfies a modified and adapted logarithmic Sobolev inequality : there exist three constant $A,B,D>0$ such that for all smooth $f>0$, \\begin{equation*} \\ent{\\mu_\\Phi}{f^2}\\leq A\\int H_{\\Phi}\\PAR{{\\frac{f'}{f}}}f^2d\\mu_\\Phi, \\text{with} H_{\\Phi}(x)= {\\begin{array}{rl} \\Phi^*\\PAR{Bx} &\\text{if }\\ABS{x}\\geq D, x^2 &\\text{if}\\ABS{x}\\leq D. \\end{array} . \\end{equation*}", "revisions": [ { "version": "v1", "updated": "2005-03-25T08:58:54.000Z" } ], "analyses": { "keywords": [ "modified logarithmic sobolev inequalities", "null curvature", "adapted logarithmic sobolev inequality", "symmetric convex function", "log-concave measure" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2005math......3585G" } } }