Flexible subspace iteration with moments for an effective contour integration-based eigensolver

TL;DR

This paper introduces a flexible subspace iteration method using moments to improve the efficiency and robustness of contour integration-based eigensolvers for large interior eigenvalue problems.

Contribution

It explores heuristics for selecting and applying moments in contour integration schemes, demonstrating improved performance, accuracy, and robustness.

Findings

Heuristic choices of moments enhance scheme performance.

Multiple moments reduce computational costs.

The proposed methods are robust across various scenarios.

Abstract

Contour integration schemes are a valuable tool for the solution of difficult interior eigenvalue problems. However, the solution of many large linear systems with multiple right hand sides may prove a prohibitive computational expense. The number of right hand sides, and thus, computational cost may be reduced if the projected subspace is created using multiple moments. In this work, we explore heuristics for the choice and application of moments with respect to various other important parameters in a contour integration scheme. We provide evidence for the expected performance, accuracy, and robustness of various schemes, showing that good heuristic choices can provide a scheme featuring good properties in all three of these measures.