===firstname:
Charles
===firstname3:

===affil6:

===lastname3:

===email:
cmorgens@mymail.mines.edu
===keyword_other2:

===lastname6:

===affil5:

===lastname4:

===lastname7:

===affil7:

===postal:
Applied Mathematics & Statistics
1500 Illinois St.
Golden, Colorado 80401
===ABSTRACT:
Large scale scientific computing models, requiring iterative algebraic solvers, 
are needed to simulate high-frequency wave propagation. 
This is because large degrees of freedom are needed to avoid the celebrated Helmholtz computer model pollution effects. 
Using low-order finite difference or finite element methods (FDM/FEM), such issues have been well investigated for low and medium frequency models (typically at most $50$ wavelengths per diameter of the wave propagation domain).
Standard FDM/FEM based discretizations of the time-harmonic Helmholtz wave propagation model lead to sign-indefinite systems with eigenvalues in the left half of the complex plane. 
Hence standard iterative methods (such as GMRES/BiCGstab) perform poorly, and additional techniques such as multigrid (MG) or decomposition of the  domain are required for efficient and practical  simulation of high-frequency  FDM/FEM  Helmholtz models. 
In this work,  we investigate the use of multiple additive Schwarz type domain decomposition (DD)  approximations to efficiently simulate  high-frequency wave propagation with high-order FEM.
We compare our DD based results with those obtained using a standard geometric MG approach for over $100$ wavelength models. 
===affil3:

===title:
Efficient  Simulation of High-Frequency Wave Propagation Using Domain Decomposition  and High-Order FEM
===affil2:
Colorado School of Mines
===lastname2:
Ganesh
===firstname4:

===keyword1:
APP_OTHER
===workshop:
no
===lastname:
Morgenstern
===firstname5:

===keyword2:
Solvers for indefinite systems
===otherauths:

===affil4:

===competition:
yes
===firstname7:

===firstname6:

===keyword_other1:
Wave Propagation
===lastname5:

===affilother:

===firstname2:
Mahadevan