A method for the Eigenreduction of real Symmetric Matrices
This paper is concerned with the problem of computing a small number of eigenvalues of large sparse generalized eigenvalue problems. The matrices arise from mixed finite element discretizations of time dependent equations modelling viscous incompressible flow. The eigenvalues of importance are those with smallest real part and are used to determine the linearized stability of steady states, and could be used in a scheme to detect Hopf bifurcations. We introduce a modified Cayley transform of the...
An ray pattern is called a spectrally arbitrary ray pattern if the complex matrices in give rise to all possible complex polynomials of degree . In a paper of Mei, Gao, Shao, and Wang (2014) was proved that the minimum number of nonzeros in an irreducible spectrally arbitrary ray pattern is . In this paper, we introduce a new family of spectrally arbitrary ray patterns of order with exactly nonzeros.
By properties of Cvetković-Kostić-Varga-type (or, for short, CKV-type) B-matrices, a new class of nonsingular matrices called CKV-type -matrices is given, and a new inclusion interval of the real eigenvalues of real matrices is presented. It is shown that the new inclusion interval is sharper than those provided by J. M. Peña (2003), and by H. B. Li et al. (2007). We also propose a direct algorithm for computing the new inclusion interval. Numerical examples are included to illustrate the effectiveness...