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Efficient rational filter-based interior eigensolvers / eingereicht von Sarah Huber, M. Sc. Wuppertal, [2021]
Inhalt
Acknowledgments
Abstract
Foreword
Contents
Motivation and outline
Introduction
Fundamentals from numerical linear algebra
Hermitian and Hermitian positive definite matrices
Orthogonality and B-orthogonality
Sparse matrices
Projection
Matrix decomposition
Eigenvalues and eigenvectors
Hermitian eigenproblems
Interior eigenproblem
Spectral projection
Building blocks for iterative eigensolvers
Power method
Krylov subspace methods
Basic subspace iteration
Rayleigh–Ritz
Subspace filtration methods
Subspace filtration
Partial spectral projector
Rational filters
Contour integration
Numerical integration
Composite midpoint rule
Gauss-Legendre quadrature
Mapping to a complex contour
Moments and rational filters
Rational filter-based eigensolvers
RFEs with moments
Convergence of an RFE
History of the RFE
Polynomial filters
Chebyshev polynomials
Additional algorithmic considerations
Solving linear systems of equations
Direct solvers
Iterative solvers
Orthogonalization
A software framework for iterative subspace filtration
Main algorithmic choices
Parallelism
Precision
Linear solvers
Conclusion
Mixed precision
Introduction
Background
Varying precision within a projected subspace iteration
Algorithmic components
Methodology
Numerical experiments
Precision changes over subspace iterations
Numerical experiments
Conclusions
Optimizing rational filters
Introduction
Convergence of an RFE
Numerical example - subspace size and convergence
Other rational filters
Zolotarev
SliSe and WiSe
Least-squares filters
Pole placement and iterative solvers
Iterative solver convergence
Kaczmarz sweeps and CG acceleration
Kaczmarz sweeps
CGMN
Parallelization and block multicoloring
Implementation of CGMN
Predicting cost
Analyzing the behaviour of CGMN
Condition number relationship
Analyzing the behaviour of GMRES
Predicting RFE iterations
Choosing weights
Optimization
Cost function
Visualization of cost function
Optimization scheme
Numerical Results
Numerical results for CGMN
Numerical results for GMRES
Comparing to other optimized filters
Conclusions
RFEs with multiple moments
Algorithmic overview
Extraction of eigenvalues and eigenvectors
Subspace iteration
Subspace size
Multiple moments
Numerical experiments
Eigenvalue counting
Extension of the BEAST framework
Definition of cost metrics
Quadrature rule
Numerical experiments
Considerations for larger problems
Rank and orthogonalization
Solution of linear systems
Numerical experiments
Parallelism and quadrature nodes
Choosing the quadrature degree
Predicting degree for a single iteration
Numerical experiments
Conclusion
Conclusions and outlook
Summary of test problems
List of Figures
List of Tables
List of Notations
Bibliography