Spectral Analysis of the Discrete Helmholtz Operator Preconditioned with a Shifted Laplacian
Spectral Analysis of the Discrete Helmholtz Operator Preconditioned with a Shifted Laplacian
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DOI:
10.1137/060661491
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发表时间:
2007-09
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影响因子:
--
通讯作者:
M. Gijzen;Y. Erlangga;C. Vuik
中科院分区:
文献类型:
--
作者:
M. Gijzen;Y. Erlangga;C. Vuik
Shifted Laplace preconditioners have attracted considerable attention as a technique to speed up convergence of iterative solution methods for the Helmholtz equation. In this paper we present a comprehensive spectral analysis of the Helmholtz operator preconditioned with a shifted Laplacian. Our analysis is valid under general conditions. The propagating medium can be heterogeneous, and the analysis also holds for different types of damping, including a radiation condition for the boundary of the computational domain. By combining the results of the spectral analysis of the preconditioned Helmholtz operator with an upper bound on the GMRES-residual norm we are able to provide an optimal value for the shift, and to explain the meshdependency of the convergence of GMRES preconditioned with a shifted Laplacian. We illustrate our results with a seismic test problem.