Logarithmic Sobolev, Hardy and Poincar\'e inequalities on the Heisenberg group

Abstract

In this paper we first prove a number of important inequalities with explicit constants in the setting of the Heisenberg group. This includes the fractional and integer Sobolev, Gagliardo-Nirenberg, (weighted) Hardy-Sobolev, Nash inequalities, and their logarithmic versions. In the case of the first order Sobolev inequality, our constant recovers the sharp constant of Jerison and Lee. Remarkably, we also establish the analogue of the Gross inequality with a semi-probability measure on the Heisenberg group that allows -- as it happens in the Euclidean setting -- an extension to infinite dimensions, and particularly can be regarded as an inequality on the infinite dimensional $\mathbb{H}^{\infty}$. Finally, we prove the so-called generalised Poincar\'e inequality on the Heisenberg group both with respect to the aforementioned semi-probability measure and the Haar measure, also with explicit constants.