Title
Efficient resonance computations for Helmholtz problems based on a Dirichlet-to-Neumann map.
Abstract
We present an efficient procedure for computing resonances and resonant modes of Helmholtz problems posed in exterior domains. The problem is formulated as a nonlinear eigenvalue problem (NEP), where the nonlinearity arises from the use of a Dirichlet-to-Neumann map, which accounts for modeling unbounded domains. We consider a variational formulation and show that the spectrum consists of isolated eigenvalues of finite multiplicity that only can accumulate at infinity. The proposed method is based on a high order finite element discretization combined with a specialization of the Tensor Infinite Arnoldi method (TIAR). Using Toeplitz matrices, we show how to specialize this method to our specific structure. In particular we introduce a pole cancellation technique in order to increase the radius of convergence for computation of eigenvalues that lie close to the poles of the matrix-valued function. The solution scheme can be applied to multiple resonators with a varying refractive index that is not necessarily piecewise constant. We present two test cases to show stability, performance and numerical accuracy of the method. In particular the use of a high order finite element discretization together with TIAR results in an efficient and reliable method to compute resonances.
Year
DOI
Venue
2018
10.1016/j.cam.2017.08.012
Journal of Computational and Applied Mathematics
Keywords
Field
DocType
Nonlinear eigenvalue problems,Helmholtz problem,Scattering resonances,Dirichlet-to-Neumann map,Arnoldi’s method,Matrix functions
Discretization,Mathematical optimization,Radius of convergence,Matrix (mathematics),Mathematical analysis,Helmholtz free energy,Finite element method,Toeplitz matrix,Piecewise,Mathematics,Eigenvalues and eigenvectors
Journal
Volume
ISSN
Citations 
330
0377-0427
0
PageRank 
References 
Authors
0.34
15
3
Name
Order
Citations
PageRank
Juan Carlos Araujo-Cabarcas100.34
Christian Engström2134.97
Jarlebring Elias38411.48