Dirichlet heat kernel estimates for isotropic Levy processes with Gaussian components in Lipschitz open sets
Jie-Ming Wang
TL;DR
This work achieves the two-sided Dirichlet heat kernel estimates for isotropic Lévy processes with Gaussian components in Lipschitz open sets, revealing that Varopoulos-type estimates may fail off-diagonal in such domains. By developing a probabilistic framework based on the time-space process, parabolic Harnack inequalities, Carleson estimates, and careful analysis of exit times and survival probabilities, the authors obtain near-diagonal two-sided bounds and off-diagonal bounds that couple the global heat kernel with boundary survival. They establish necessary and sufficient conditions for Varopoulos-type Dirichlet heat kernel estimates, showing they are equivalent to a scale-invariant boundary Harnack principle for these processes. As an application, they derive explicit two-sided Dirichlet heat kernel estimates in $C^{1,1}$ domains, connecting Green functions, exit times, and heat kernels in a unified probabilistic framework. The results illuminate boundary behavior of nonlocal operators with Gaussian components and extend the scope of Varopoulos-type estimates beyond purely local or purely nonlocal settings.
Abstract
In this paper, the two-sided Dirichlet heat kernel estimates are obtained for a class of discontinuous isotropic Levy processes with Gaussian components in Lipschitz open sets. Furthermore, the necessary and sufficient conditions for the Varopoulos-type Dirichlet heat kernel estimates holding for such processes in Lipschitz open sets are derived.
