Transverse electric scattering on inhomogeneous objects: Spectrum of integral operator and preconditioning

Zouros, GP; Budko, NV

dc.contributor.author	Zouros, GP	en
dc.contributor.author	Budko, NV	en
dc.date.accessioned	2014-03-01T02:14:51Z
dc.date.available	2014-03-01T02:14:51Z
dc.date.issued	2012	en
dc.identifier.issn	10648275	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/30154
dc.subject	Deflation	en
dc.subject	Domain integral equation	en
dc.subject	Electromagnetism	en
dc.subject	Essential spectrum	en
dc.subject	Preconditioner	en
dc.subject	Regularizer	en
dc.subject	Singular integral operators	en
dc.subject	Spectrum of operators	en
dc.subject	Transverse electric scattering	en
dc.subject.other	Deflation	en
dc.subject.other	Essential spectrum	en
dc.subject.other	Preconditioners	en
dc.subject.other	Regularizer	en
dc.subject.other	Singular integral operators	en
dc.subject.other	Transverse electric scattering	en
dc.subject.other	Eigenvalues and eigenfunctions	en
dc.subject.other	Electromagnetism	en
dc.subject.other	Fast Fourier transforms	en
dc.subject.other	Integral equations	en
dc.subject.other	Vector spaces	en
dc.subject.other	Scattering	en
dc.title	Transverse electric scattering on inhomogeneous objects: Spectrum of integral operator and preconditioning	en
heal.type	journalArticle	en
heal.identifier.primary	10.1137/110831568	en
heal.identifier.secondary	http://dx.doi.org/10.1137/110831568	en
heal.publicationDate	2012	en
heal.abstract	The domain integral equation method with its FFT-based matrix-vector products is a viable alternative to local methods in free-space scattering problems. However, it often suffers from the extremely slow convergence of iterative methods, especially in the transverse electric (TE) case with large or negative permittivity. We identify very dense line segments in the spectrum as being partly responsible for this behavior and the main reason why a normally efficient deflating preconditioner does not work. We solve this problem by applying an explicit multiplicative regularizing operator, which on the operator level transforms the system to the form ""identity plus compact."" On the matrix level this regularization reduces the length of the dense spectral segments roughly by a factor of four while preserving the ability to calculate the matrix-vector products using the FFT algorithm. Such a regularized system is then further preconditioned by deflating an apparently stable set of eigenvalues with largest magnitudes, which results in a robust acceleration of the restarted GMRES under constraint memory conditions. © 2012 Society for Industrial and Applied Mathematics.	en
heal.journalName	SIAM Journal on Scientific Computing	en
dc.identifier.doi	10.1137/110831568	en
dc.identifier.volume	34	en
dc.identifier.issue	3	en
dc.identifier.spage	B226	en
dc.identifier.epage	B246	en