Author(s) :
Jörg Liesen
Preprint series of the Institute of Mathematics, Technische Universität Berlin
Preprint 10-2006
MSC 2000
- 65F15 Eigenvalues, eigenvectors
-
65N22 Solution of discretized equations
Abstract :
Results of Benzi and Simoncini (Numer. Math. 103 (2006), pp.~173--196)
on spectral properties of block $2\times 2$ matrices are generalized
to the case of a symmetric positive semidefinite block at the (2,2)
position. More precisely, a sufficient condition is derived when a
(nonsymmetric) saddle point matrix of the form $[A\;\;B^T; -B\;C]$
with $A=A^T>0$, full rank $B$, and $C=C^T\geq 0$, is diagonalizable
and has real and positive eigenvalues.
Keywords :
saddle point problem, eigenvalues, Stokes problem, normal matrices