On domination for (non-symmetric) Dirichlet forms

TL;DR

This paper explores the relationship between semigroup domination and Dirichlet forms, establishing equivalences with killing transformations and characterizing sandwiched operators with boundary conditions.

Contribution

It generalizes previous results by linking domination of Dirichlet forms to killing transformations and provides new characterizations of sandwiched operators with boundary conditions.

Findings

Established equivalence between domination of Dirichlet forms and killing transformations.

Provided a representation of dominated Dirichlet forms via bivariate Revuz measures.

Characterized operators between Dirichlet and Neumann Laplacians, including Robin boundary conditions.

Abstract

The primary aim of this article is to investigate the domination relationship between two $L^2$-semigroups using probabilistic methods. According to Ouhabaz's domination criterion, the domination of semigroups can be transformed into relationships involving the corresponding Dirichlet forms. Our principal result establishes the equivalence between the domination of Dirichlet forms and the killing transformation of the associated Markov processes, which generalizes and completes the results in \cite{Y962} and \cite{Y96}. Based on this equivalence, we provide a representation of the dominated Dirichlet form using the bivariate Revuz measure associated with the killing transformation and further characterize the sandwiched Dirichlet form within the broader Dirichlet form framework. In particular, our findings apply to the characterization of operators sandwiched between the Dirichlet Laplacian and the Neumann Laplacian. For the local boundary case, we eliminate all technical conditions identified in the literature \cite{AW03} and deliver a complete representation of all sandwiched operators governed by a Robin boundary condition determined by a specific quasi-admissible measure. Additionally, our results offer a comprehensive characterization of related operators in the non-local Robin boundary case, specifically resolving an open problem posed in the literature \cite{OA21}.