Results 1 to 10 of about 448 (54)
Operators and Matrices, 2021 In this paper, rectangular matrices whose minors of a given order have the same strict sign are considered and sufficient conditions for their recognition are presented.
Rola Alseidi, J. Garloff
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On the similarity to nonnegative and Metzler Hessenberg forms
Special Matrices, 2021 We address the issue of establishing standard forms for nonnegative and Metzler matrices by considering their similarity to nonnegative and Metzler Hessenberg matrices.
Grussler Christian, Rantzer Anders
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An elementary proof of Chollet’s permanent conjecture for 4 × 4 real matrices
Special Matrices, 2021 A proof of the statement per(A ∘ B) ≤ per(A)per(B) is given for 4 × 4 positive semidefinite real matrices. The proof uses only elementary linear algebra and a rather lengthy series of simple inequalities.
Hutchinson George
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A trace bound for integer-diagonal positive semidefinite matrices
Special Matrices, 2020 We prove that an n-by-n complex positive semidefinite matrix of rank r whose graph is connected, whose diagonal entries are integers, and whose non-zero off-diagonal entries have modulus at least one, has trace at least n + r − 1.
Mitchell Lon
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Doubly constrained totally positive line insertion
Special Matrices, 2020 It is shown that in any TP matrix, a line (row or column) with two speci˝ed entries in any positions (and the others appropriately chosen) may be inserted in any position, as long as the two entries are consistent with total positivity.
Johnson Charles R., Allen David W.
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The Totally Positive Completion Problem: The 3-by-n Case
Special Matrices, 2021 The 3-by-n TP-completable patterns are characterized by identifying the minimal obstructions up to natural symmetries. They are finite in number.
Carter D. +4 more
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A note on Bapat's q-permanent conjecture
, 2020 Ravindra Bapat conjectured the q -permanent of a non-diagonal Hermitian positive definite matrix is a strictly increasing (in q ) interpolation between the determinant (q = −1) and the permanent (q = 1).
Lon H. Mitchell
semanticscholar +1 more source
On the polyhedral cones of convex and concave vectors [PDF]
, 2013 Convex or concave sequences of n positive terms, viewed as vectors in n-space, constitute convex cones with 2n − 2 and n extreme rays, respectively.
Foldes, Stephan, Major, Laszlo
core +2 more sources
On hyponormality on a weighted annulus
Open Mathematics, 2021 In this work, we consider the hyponormality of Toeplitz operators on the Bergman space of the annulus with a logarithmic weight. We give necessary conditions when the symbol is of the form φ+ψ¯\varphi +\overline{\psi }, where φ\varphi and ψ\psi are ...
Sadraoui Houcine +2 more
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Extensions of pseudo-Perron-Frobenius splitting related to generalized inverse AT,S(2)
Special Matrices, 2018 We in this paper define the outer-Perron-Frobenius splitting, which is an extension of the pseudo- Perron-Frobenius splitting defined in [A.N. Sushama, K. Premakumari, K.C.
Huang Shaowu +3 more
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