Logarithmic Sobolev-type inequalities on Lie groups

TL;DR

This paper establishes various logarithmic inequalities on Lie groups, including log-Sobolev, Gagliardo-Nirenberg, and Caffarelli-Kohn-Nirenberg inequalities, with applications to heat equation decay rates and weighted inequalities.

Contribution

It introduces new log-Sobolev and related inequalities on general and stratified Lie groups, including Gaussian measure versions and weighted forms, extending classical results.

Findings

Log-Sobolev inequalities on general Lie groups

Weighted Gross log-Sobolev inequalities with Gaussian measure

Nash inequalities and heat decay estimates on stratified groups

Abstract

In this paper we show a number of logarithmic inequalities on several classes of Lie groups: log-Sobolev inequalities on general Lie groups, log-Sobolev (weighted and unweighted), log-Gagliardo-Nirenberg and log-Caffarelli-Kohn-Nirenberg inequalities on graded Lie groups. Furthermore, on stratified groups, we show that one of the obtained inequalities is equivalent to a Gross-type log-Sobolev inequality with the horizontal gradient. As a result, we obtain the Gross log-Sobolev inequality on general stratified groups but, {\bf very interestingly}, with the Gaussian measure on the first stratum of the group. Moreover, our methods also yield weighted versions of the Gross log-Sobolev inequality. In particular, we also obtain new weighted Gross-type log-Sobolev inequalities on $\mathbb R^n$ for arbitrary choices of homogeneous quasi-norms. As another consequence we derive the Nash inequalities on graded groups and an example application to the decay rate for the heat equations for sub-Laplacians on stratified groups. We also obtain weighted versions of log-Sobolev and Nash inequalities for general Lie groups.