Results 1 to 10 of about 1,075 (62)
A note on certain ergodicity coeflcients
Special Matrices, 2015 We investigate two ergodicity coefficients ɸ ∥∥ and τn−1, originally introduced to bound the subdominant eigenvalues of nonnegative matrices. The former has been generalized to complex matrices in recent years and several properties for such generalized ...
Tudisco Francesco
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An ℋ-tensor-based criteria for testing the positive definiteness of multivariate homogeneous forms
Open Mathematics, 2022 A positive definite homogeneous multivariate form plays an important role in the field of optimization, and positive definiteness of the form can be identified by a special structured tensor.
Bai Dongjian, Wang Feng
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Open Mathematics, 2021 Positive definite polynomials are important in the field of optimization. ℋ-tensors play an important role in identifing the positive definiteness of an even-order homogeneous multivariate form.
Sun Deshu, Bai Dongjian
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On Regular Signed Graphs with Three Eigenvalues
Discussiones Mathematicae Graph Theory, 2020 In this paper our focus is on regular signed graphs with exactly 3 (distinct) eigenvalues. We establish certain basic results; for example, we show that they are walk-regular.
Anđelić Milica +2 more
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Eigenvalue inclusion sets for linear response eigenvalue problems
Demonstratio Mathematica, 2022 In this article, some inclusion sets for eigenvalues of a matrix in the linear response eigenvalue problem (LREP) are established. It is proved that the inclusion sets are tighter than the Geršgorin-type sets.
He Jun, Liu Yanmin, Lv Wei
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A modified variant of HSS preconditioner for generalized saddle point problems
Advances in Mechanical Engineering, 2022 Recently, Zhang [Numerical Linear Algebra with Applications, 2018: e2166] constructed an efficient variant of Hermitian and skew-Hermitian splitting (HSS) preconditioner for generalized saddle point problems, and gave the corresponding theoretical ...
Li-Tao Zhang, Yi-Fan Zhang
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A new generalized shift-splitting method for nonsymmetric saddle point problems
Advances in Mechanical Engineering, 2022 Recently, Huang and Huang [ Journal of Computational and Applied Mathematics , 328 (2018) 381–399] proposed a modified generalized shift-splitting preconditioned (denoted by MGSSP) method for solving large sparse saddle point problems, and gave the ...
Tao Wei, Li-Tao Zhang
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The calculation of the distance to a nearby defective matrix [PDF]
, 2012 In this paper a new fast algorithm for the computation of the distance of a matrix to a nearby defective matrix is presented. The problem is formulated following Alam & Bora (Linear Algebra Appl., 396 (2005), pp.~273--301) and reduces to finding when a ...
Freitag, Melina A., Spence, Alastair
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Perturbations in a Signed Graph and its Index
Discussiones Mathematicae Graph Theory, 2018 In this paper we consider the behaviour of the largest eigenvalue (also called the index) of signed graphs under small perturbations like adding a vertex, adding an edge or changing the sign of an edge.
Stanić Zoran
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Compression of unitary rank--structured matrices to CMV-like shape with an application to polynomial rootfinding [PDF]
, 2013 This paper is concerned with the reduction of a unitary matrix U to CMV-like shape. A Lanczos--type algorithm is presented which carries out the reduction by computing the block tridiagonal form of the Hermitian part of U, i.e., of the matrix U+U^H.
Bevilacqua, Roberto +2 more
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