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Use of Shifted Laplacian Operators for Solving Indefinite Helmholtz Equations

Published online by Cambridge University Press:  03 March 2015

Ira Livshits*
Affiliation:
Department of Mathematical Sciences, Ball State University, Muncie IN, 47306, USA
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Abstract

A shifted Laplacian operator is obtained from the Helmholtz operator by adding a complex damping. It serves as a basic tool in the most successful multigrid approach for solving highly indefinite Helmholtz equations — a Shifted Laplacian preconditioner for Krylov-type methods. Such preconditioning significantly accelerates Krylov iterations, much more so than the multigrid based on original Helmholtz equations. In this paper, we compare approximation and relaxation properties of the Helmholtz operator with and without the complex shift, and, based on our observations, propose a new hybrid approach that combines the two. Our analytical conclusions are supported by two-dimensional numerical results.

Type
Research Article
Copyright
Copyright © Global-Science Press 2015 

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References

[1]Bayliss, A., Goldstein, C.I., and Turkel, E.. An iterative method for the helmholtz equation. Journal of Computational Physics, 49(3):443457, 1983.CrossRefGoogle Scholar
[2]Brandt, A. and Livshits, I.. Wave-ray multigrid method for standing wave equations. Electron. Trans. Numer. Anal., pages 162181, 1997.Google Scholar
[3]Elman, H.C., Ernst, O.G., and O’Leary, D.P.. A multigrid method enhanced by krylov subspace iteration for discrete helmholtz equations. SIAM J. Sci. Comput., 23(4):12911315, 2001.CrossRefGoogle Scholar
[4]Erlangga, Y.A. and Nabben, R.. On a multilevel krylov method for the helmholtz equation preconditioned by shifted laplacian. Electron. Trans. Numer. Anal., (31):403424, 2008.Google Scholar
[5]Erlangga, Y.A., Oosterlee, C.W., and Vuik, C.. A novel multigrid based preconditioner for heterogeneous helmholtz problems. SIAM J. Sci. Comput., 27(4):14711492, 2006.CrossRefGoogle Scholar
[6]Erlangga, Y.A., Vuik, C., and Oosterlee, C.W.. On a class of preconditioners for solving the helmholtz equation. Appl. Numer. Math., 50(3–4):40425, 2004.CrossRefGoogle Scholar
[7]Erlangga, Y.A., Vuik, C., and Oosterlee, C.W.. On a robust iterative method for heterogeneous helmholtz problems for geophysics applications. Int. J. Numer. Anal. Model., (2):197208, 2005.Google Scholar
[8]Erlangga, Y.A., Vuik, C., and Oosterlee, C.W.. Comparison of multigrid and incomplete lu shifted-laplace preconditioners for the inhomogeneous helmholtz equation. Appl. Numer. Math., (56):648666, 2006.CrossRefGoogle Scholar
[9]Ernst, O.G. and Gander, M.J.. Why it is difficult to solve helmholtz problems with classical iterative methods. In Numerical Analysis of Multiscale Problems. Springer Berlin Heidelberg, 2012.Google Scholar
[10]Haber, E. and MacLachlan, S.. A fast method for the solution of the helmholtz equation. J. Comp. Phys., 230:44034418, 2011.CrossRefGoogle Scholar
[11]Livshits, I. A scalable multigrid method for solving the indefinite helmholtz equation with constant wave numbers. Numerical Linear Algebra and Applications, 21(2):177193, 2014.CrossRefGoogle Scholar
[12]Kaczmarz, S.. Angenaherte auflosung von systemen linearer gleichungen. Bulletin International de l’Académia Polonaise des Sciences et des Lettres. Classe des Sciences Mathématiques et Naturalles. SérieA., Sciences Mathématiques, 35:355357, 1937.Google Scholar
[13]Lee, B., Manteuffel, T.A., McCormick, S.F., and Ruge, J.. First-order system least-squares for the helmholtz equation. SIAM J. Sci. Comput., 21(5):19271949, 2000.CrossRefGoogle Scholar
[14]Olson, L.N. and Schroder, J.B.. Smoothed aggregation for helmholtz problems. Numerical Linear Algebra and Applications, 17(2–3):361386, 2010.CrossRefGoogle Scholar
[15]Sheikh, A., Lahaye, D., and Vuik, C.. A scalable helmholtz solver combining the shifted laplace preconditioner with multigrid deflation. Numer. Linear Algebra Appl., 20:645662.CrossRefGoogle Scholar
[16]Umetani, N., MacLachlan, S.P., and Oosterlee, C.W.. A multigrid-based shifted- laplacian preconditioner for a fourth-order helmholtz discretization. Numer. Linear Alg. Appl., 16:603626, 2006.CrossRefGoogle Scholar
[17]Vanek, P., Mandel, J., and Brezina, M.. Two-level algebraic multigrid for the helmholtz problem. In Domain decomposition methods 10, 218:349356, 1998.CrossRefGoogle Scholar