Weighted Poincar\'e inequality and Hardy improvements related to some degenerate elliptic differential operators

TL;DR

This paper characterizes sharp constants and maximizers for weighted Poincaré inequalities, leading to improved Hardy inequalities with remainder terms, applicable in Euclidean and non-Euclidean settings like the Heisenberg and Carnot groups.

Contribution

It introduces a novel technique avoiding symmetric rearrangement to analyze inequalities across diverse geometric contexts.

Findings

Sharp constants and maximizers identified for weighted Poincaré inequalities.

Refined Hardy inequalities with additional remainder terms established.

Method applicable to various non-Euclidean operators such as Heisenberg-Greiner and Baouendi-Grushin.

Abstract

In this paper, we characterize the sharp constant and maximizing functions for weighted Poincar\'e inequalities. These results lead to refinements of Hardy's inequality obtained by adding remainder terms involving \(L^p\) norms. We use techniques that avoid symmetric rearrangement argument, simplifying the analysis of these inequalities in both Euclidean and non-Euclidean contexts. Specifically, this method applies to a variety of settings, such as the Heisenberg group, various Carnot groups and operators expressed as sums of squares of vector fields. Significant examples include the Heisenberg-Greiner operator and the Baouendi-Grushin operator.