Caffarelli-Kohn-Nirenberg identities, inequalities and their stabilities

TL;DR

This paper introduces a unified family of inequalities encompassing Hardy and Caffarelli-Kohn-Nirenberg inequalities, analyzes their sharp constants, and explores stability and optimizer existence, advancing understanding of these fundamental inequalities.

Contribution

It develops a one-parameter family of inequalities, studies their sharpness and stability, and applies these results to the Heisenberg Uncertainty Principle.

Findings

Established sharp versions with optimal constants.

Proved stability of the Heisenberg Uncertainty Principle.

Analyzed existence and non-existence of optimizers.

Abstract

We set up a one-parameter family of inequalities that contains both the Hardy inequalities (when the parameter is 1) and the Caffarelli-Kohn-Nirenberg inequalities (when the parameter is optimal). Moreover, we study these results with the exact remainders to provide direct understandings to the sharp constants, as well as the existence and non-existence of the optimizers of the Hardy inequalities and Caffarelli-Kohn-Nirenberg inequalities. As an application of our identities, we establish some sharp versions with optimal constants and theirs attainability of the stability of the Heisenberg Uncertainty Principle and several stability results of the Caffarelli-Kohn-Nirenberg inequalities.