A domain decomposition method for stochastic evolution equations
Evelyn Buckwar, Ana Djurdjevac, Monika Eisenmann
TL;DR
This work develops a domain-decomposition operator splitting framework for stochastic evolution equations, enabling parallel sub-domain solves through an IMEX Euler–Maruyama time-stepping scheme and a Lie-splitting assembly. It provides a rigorous variational-analytical foundation, including existence and regularity results, a well-posedness proof for the implicit subproblems, and a mean-square error bound that scales with the time-step size via $h^{2\nu}$ plus a truncation error $\varepsilon$. The domain-decomposition instantiation for a stochastic heat equation demonstrates how local sub-operators can be coupled to recover the global solution with controlled accuracy. Numerical experiments in 2D validate the theoretical convergence rate (approximately $\tfrac{1}{2}$) for both additive and multiplicative noise, highlighting the method’s practicality and parallelizability for SPDEs.
Abstract
In recent years, SPDEs have become a well-studied field in mathematics. With their increase in popularity, it becomes important to efficiently approximate their solutions. Thus, our goal is a contribution towards the development of efficient and practical time-stepping methods for SPDEs. Operator splitting schemes are a powerful tool for deterministic and stochastic differential equations. An example is given by domain decomposition schemes, where we split the domain into sub-domains. Instead of solving one expensive problem on the entire domain, we deal with cheaper problems on the sub-domains. This is particularly useful in modern computer architectures, as the sub-problems may often be solved in parallel. While splitting methods have already been used to study domain decomposition methods for deterministic PDEs, this is a new approach for SPDEs. We provide an abstract convergence analysis of a splitting scheme for stochastic evolution equations and state a domain decomposition scheme as an application of the setting. The theoretical results are verified through numerical experiments.
