On the log-Sobolev constant of log-concave measures

Abstract: It is well known that a log-Sobolev inequality implies sub-gaussian decay of the tails. In the spirit of the KLS conjecture, we investigate whether this implication can be reversed under a log-concavity assumption. In the general setting, we improve on a result of Bobkov, establishing the best dimension dependent bound on the log-Sobolev constant of subgaussian log-concave measures, and we investigate some special cases.