A necessary and sufficient condition for stability of the convex combination of polynomials
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...