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arXiv · 2001.07930

Rigidity of some functional inequalities on RCD spaces

Bang-Xian Han
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Abstract

We study the cases of equality and prove a rigidity theorem concerning the 1-Bakry-\'Emery inequality. As an application, we prove the rigidity of the Gaussian isoperimetric inequality, the logarithmic Sobolev inequality and the Poincar\'e inequality in the setting of ${\rm RCD}(K, \infty)$ metric measure spaces. This unifies and extends to the non-smooth setting the results of Carlen-Kerce, Morgan, Bouyrie, Ohta-Takatsu, Cheng-Zhou. Examples of non-smooth spaces fitting our setting are measured-Gromov Hausdorff limits of Riemannian manifolds with uniform Ricci curvature lower bound, and Alexandrov spaces with curvature lower bound. Some results including the rigidity of $\Phi$-entropy inequalities, the rigidity of the 1-Bakry-\'Emery inequality are of independent interest even in the smooth setting.

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Bang-Xian Han. 2020-01-22. Rigidity of some functional inequalities on RCD spaces. https://arxiv.org/abs/2001.07930

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