Domain decomposition schemes for evolutionary equations of first order with not self-adjoint operators

TL;DR

This paper develops unconditionally stable, iteration-free domain decomposition schemes for first-order evolutionary equations with non-self-adjoint operators, extending previous methods to more general operators in finite-dimensional Hilbert spaces.

Contribution

It introduces new domain decomposition schemes for non-self-adjoint operators, ensuring stability and nonnegativity preservation, expanding the applicability of additive operator-difference methods.

Findings

Constructed decomposition operators preserving nonnegativity.

Developed unconditionally stable additive schemes based on regularization.

Validated methods with a 2D parabolic equation model problem.

Abstract

Domain decomposition methods are essential in solving applied problems on parallel computer systems. For boundary value problems for evolutionary equations the implicit schemes are in common use to solve problems at a new time level employing iterative methods of domain decomposition. An alternative approach is based on constructing iteration-free methods based on special schemes of splitting into subdomains. Such regionally-additive schemes are constructed using the general theory of additive operator-difference schemes. There are employed the analogues of classical schemes of alternating direction method, locally one-dimensional schemes, factorization methods, vector and regularized additive schemes. The main results were obtained here for time-dependent problems with self-adjoint elliptic operators of second order. The paper discusses the Cauchy problem for the first order evolutionary equations with a nonnegative not self-adjoint operator in a finite-dimensional Hilbert space. Based on the partition of unit, we have constructed the operators of decomposition which preserve nonnegativity for the individual operator terms of splitting. Unconditionally stable additive schemes of domain decomposition were constructed using the regularization principle for operator-difference schemes. Vector additive schemes were considered, too. The results of our work are illustrated by a model problem for the two-dimensional parabolic equation.