Search results for "Normal matrix"

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Inverse eigenvalue problem for normal J-hamiltonian matrices

2015

[EN] A complex square matrix A is called J-hamiltonian if AT is hermitian where J is a normal real matrix such that J(2) = -I-n. In this paper we solve the problem of finding J-hamiltonian normal solutions for the inverse eigenvalue problem. (C) 2015 Elsevier Ltd. All rights reserved.

Hamiltonian matrixApplied MathematicsHamiltonian matrixMoore–Penrose inverseMatrius (Matemàtica)Normal matrixSquare matrixHermitian matrixCombinatoricssymbols.namesakeMatrix (mathematics)Inverse eigenvalue problemsymbolsÀlgebra linealDivide-and-conquer eigenvalue algorithmMATEMATICA APLICADAHamiltonian (quantum mechanics)Normal matrixEigenvalues and eigenvectorsMathematicsMathematical physicsApplied Mathematics Letters
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Positive linear maps on normal matrices

2018

For a positive linear map [Formula: see text] and a normal matrix [Formula: see text], we show that [Formula: see text] is bounded by some simple linear combinations in the unitary orbit of [Formula: see text]. Several elegant sharp inequalities are derived, for instance for the Schur product of two normal matrices [Formula: see text], [Formula: see text] for some unitary [Formula: see text], where the constant [Formula: see text] is optimal.

Pure mathematicsComputer Science::Information RetrievalGeneral Mathematics010102 general mathematicsAstrophysics::Instrumentation and Methods for AstrophysicsComputer Science::Computation and Language (Computational Linguistics and Natural Language and Speech Processing)010103 numerical & computational mathematics01 natural sciencesUnitary stateNormal matrixFunctional Analysis (math.FA)Mathematics - Functional AnalysisLinear mapSimple (abstract algebra)Bounded functionFOS: MathematicsComputer Science::General Literature0101 mathematicsOrbit (control theory)Linear combinationMathematicsInternational Journal of Mathematics
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A note on k-generalized projections

2007

Abstract In this note, we investigate characterizations for k -generalized projections (i.e., A k  =  A ∗ ) on Hilbert spaces. The obtained results generalize those for generalized projections on Hilbert spaces in [Hong-Ke Du, Yuan Li, The spectral characterization of generalized projections, Linear Algebra Appl. 400 (2005) 313–318] and those for matrices in [J. Benitez, N. Thome, Characterizations and linear combinations of k -generalized projectors, Linear Algebra Appl. 410 (2005) 150–159].

Pure mathematicsNumerical AnalysisAlgebra and Number TheoryNormal matricesHilbert spaceCharacterization (mathematics)Matrius (Matemàtica)Normal matrixAlgebrasymbols.namesakeLinear algebrasymbolsDiscrete Mathematics and CombinatoricsSpectral projectionGeometry and TopologyÀlgebra linealLinear combinationProjectionst-Potent matricesMathematicsLinear Algebra and its Applications
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