Calculus of Variations and Geometric Measure Theory

L. Tamanini

From Harnack inequality to heat kernel estimates on metric measure spaces and applications

created by tamanini1 on 16 Jul 2019



Inserted: 16 jul 2019
Last Updated: 16 jul 2019

Year: 2019


Aim of this short note is to show that a dimension-free Harnack inequality on an infinitesimally Hilbertian metric measure space where the heat semigroup admits an integral representation in terms of a kernel is sufficient to deduce a sharp upper Gaussian estimate for such kernel. As intermediate step, we prove the local logarithmic Sobolev inequality (known to be equivalent to a lower bound on the Ricci curvature tensor in smooth Riemannian manifolds). Both results are new also in the more regular framework of $RCD(K,\infty)$ spaces.