TUESDAY, March 14, 9:30 am
in room AVW 3258, University of Maryland,
College Park
A Generalized Jacobi-Davidson Iteration Method for Linear
Eigenvalue Problems
Prof. Henk van der Vorst
Mathematics Institute
Utrecht University
Netherlands
vorst@math.ruu.nl
Suppose we want to compute one or more eigenvalues and their corresponding
eigenvectors of the n by n matrix A.
Several iterative methods are available: Jacobi's method, the power method,
the method of Lanczos, Arnoldi's method, and Davidson's method.
The latter method has been reported as being quite successful, most notably
in connection with certain symmetric problems in computational chemistry.
The success of the method seems to depend quite heavily on (strong) diagonal
dominance of A.
The method of Davidson is commonly seen as an extension to Lanczos' method,
but as Saad points out, from the implementation point of view it is more
related to Arnoldi's method. In spite of these relations the success of the
method is not well understood. Some recent convergence results, as well as
numerical experiments, are reported in Saad's book on eigenvalue problems
and in a recent paper by Crouzeix, Philippe and Sadkane.
However, as we will show, Davidson's method has an interesting connection
with an old and almost forgotten method of Jacobi. This leads to another
view on the method of Davidson, that may help us to explain the behaviour
of the method, and that may help to develop new algorithms for non-diagonally
dominant and unsymmetric matrices as well.
The reported work is joint research with Gerard Sleijpen.
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