Search Results - "Drury, S.W."

Fischer determinantal inequalities and Highamʼs Conjecture by Drury, S.W.

“…We obtain a Fischer type determinantal inequality for matrices with given angular numerical range. We discuss the growth factor for Gaussian elimination for…”
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Positive semidefiniteness of a 3×3 matrix related to partitioning by Drury, S.W.

“…For n a positive integer let Q1,Q2 and Q3 be n×n complex matrices. Then the 3×3 matrix M given by mjk=tr(|Qj⋆Qk|) is shown to be positive semidefinite…”
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On a question of Bhatia and Kittaneh by Drury, S.W.

“…We settle in the affirmative a question of Bhatia and Kittaneh. For P and Q positive semidefinite n×n matrices, the inequality σr(PQ)⩽12λr(P+Q) holds for…”
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Extremal digraphs with given clique number by Drury, S.W., Lin, Huiqiu

“…We classify those digraphs with a given number of vertices and a given clique number that maximize the Perron root of the adjacency matrix…”
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The maximum Perron roots of digraphs with some given parameters by Lin, Huiqiu, Drury, S.W.

“…We characterize the extremal digraphs which attain the maximum Perron root of digraphs with given arc connectivity and number of vertices. We also characterize…”
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Solution of the conjecture of Brualdi and Li by Drury, S.W.

“…We establish the conjecture of Brualdi and Li on the maximal Perron root of a tournament matrix of even order…”
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A counterexample to a conjecture of Matsaev by Drury, S.W.

“…We present an effective algorithm for estimating the norm of an operator mapping a low-dimensional ℓ p space to a Banach space with an easily computable norm…”
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Symbolic calculus of operators with unit numerical radius by Drury, S.W.

“…Let T be a linear operator on a complex Hilbert space with numerical radius bounded by one. We study the norm and numerical range of p(T) where p is a disk…”
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Von Neumann’s inequality for noncommuting contractions by Drury, S.W.

“…Let T 1 , … , T d be linear contractions on a complex Hilbert space and p a complex polynomial in d variables which is a sum of d single variable polynomials…”
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OMC for scalar multiples of unitaries by Drury, S.W.

“…We establish the following case of the Determinantal Conjecture of Marcus [M. Marcus, Derivations, Plücker relations and the numerical range, Indiana Univ…”
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The canonical correlations of a 2×2 block matrix with given eigenvalues by Drury, S.W.

“…Let 1⩽ k⩽ n/2, and A= A 11 A 12 [−1pt]A 21 A 22 be an n× n positive definite matrix so that A 11 is k× k. Suppose that A has given eigenvalues λ 1⩾⋯⩾ λ n >0…”
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Maximizing traces of matrix functions by Drury, S.W

“…Let X and Y be n× n Hermitian matrices with eigenvalues x 1⩾ x 2⩾⋯⩾ x n and y 1⩾ y 2⩾⋯⩾ y n respectively. We establish the inequality tr(ϕ(X+Y))⩽ max σ∈S n ∑…”
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OMC for Householder reflections by Drury, S.W.

“…We show that the celebrated Conjecture of Marcus and De Oliveira is correct in case the unitary matrix is a Householder reflection matrix. It is also shown…”
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Permanents and Lorentzian time-semidefinite matrices by Drury, S.W.

“…A hermitian matrix is said to be Lorentzian time-semidefinite if it has nonnegative diagonal elements and at most one positive eigenvalue. We show, using a…”
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The numerical range of products of normal matrices by Drury, S.W.

“…In an earlier paper, the author developed a formula for the trace class multiplier norm of a matrix of rank at most 2. In this article, applications of this…”
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Trace class multipliers and spectral variation of normal matrices by Drury, S.W.

“…In this article we show how to estimate the trace multiplier norm of a rank 2 matrix. As an application, an alternative proof of a theorem of Holbrook et al…”
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The determinantal conjecture and Hadamard type inequalities by Drury, S.W.

“…The first part of this paper presents an approach to a possible salvation of an idea advanced by papers of Bebiano, Merikoski, da Providência, and Virtanen for…”
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Some remarks on a conjecture of Boyle and Handelman by Ambikkumar, S., Drury, S.W.

“…Boyle and Handelman have conjectured that whenever A is an n × n nonnegative matrix with rank A ⩽ r and Perron root λ 1, the inequality det(λ I − tA) ⩽ λ n− r…”
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A reverse Hadamard inequality by Ambikkumar, S., Drury, S.W.

“…Let U be an n × n unitary matrix with determinant equal to 1. Let A be an n × n real matrix with rank( A) ⩽ 2 and entries satisfying a ij ⩾ 1 for 1 ⩽ i, j ⩽ n…”
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The Singular Value Decomposition of the Square Roots of the Identity Matrix by Goeree, Jacob, Neudecker, Heinz, Drury, S.W., Styan, George P.H.

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