Results 51 to 60 of about 2,226,866 (302)
Hilbert’s 17th problem in free skew fields
Forum of Mathematics, Sigma, 2020 This paper solves the rational noncommutative analogue of Hilbert’s 17th problem: if a noncommutative rational function is positive semidefinite on all tuples of Hermitian matrices in its domain, then it is a sum of Hermitian squares of noncommutative ...
Jurij Volčič
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The density matrix in the non-Hermitian approach to open quantum system dynamics
Atti della Accademia Peloritana dei Pericolanti : Classe di Scienze Fisiche, Matematiche e Naturali, 2019 In this paper we review an approach to the dynamics of open quantum systems based of non-Hermitian Hamiltonians. Non-Hermitian Hamiltonians arise naturally when one wish to study a subsystem interacting with a continuum of states.
Alessandro Sergi
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Butson-type complex Hadamard matrices and association schemes on Galois rings of characteristic 4
Special Matrices, 2018 We consider nonsymmetric hermitian complex Hadamard matrices belonging to the Bose-Mesner algebra of commutative nonsymmetric association schemes. First, we give a characterization of the eigenmatrix of a commutative nonsymmetric association scheme of ...
Ikuta Takuya, Munemasa Akihiro
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Non-Hermitian Generalization of Rényi Entropy
Entropy, 2022 From their conception to present times, different concepts and definitions of entropy take key roles in a variety of areas from thermodynamics to information science, and they can be applied to both classical and quantum systems.
Daili Li, Chao Zheng
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Generalized Finite Algorithms for Constructing Hermitian Matrices with Prescribed Diagonal and Spectrum [PDF]
, 2005 In this paper, we present new algorithms that can replace the diagonal entries of a Hermitian matrix by any set of diagonal entries that majorize the original set without altering the eigenvalues of the matrix.
Dhillon, Inderjit S. +3 more
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Symmetry-resolved entanglement in critical non-Hermitian systems [PDF]
, 2023 The study of entanglement in the symmetry sectors of a theory has recently attracted a lot of attention since it provides better understanding of some aspects of quantum many-body systems.
Michele Fossati, F. Ares, P. Calabrese
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The Sum Two of Hermitian Operators Ai=Ti+Mi for Solving the Equations{Ai X=Ui },i=1,2
Wasit Journal for Pure Sciences, 2023 In this work we study a new class of equations (Ti+Mi)X=Ui, i=1,2 including the sum two of Hermitian operatorsTi and Mi , i=1,2, concerning the kind of spaces are Hilbert.
Eman Sadiq
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Determination of the domain of the admissible matrix elements in the four-dimensional PT-symmetric anharmonic model [PDF]
, 2007 Many manifestly non-Hermitian Hamiltonians (typically, PT-symmetric complex anharmonic oscillators) possess a strictly real, "physical" bound-state spectrum. This means that they are (quasi-)Hermitian with respect to a suitable non-standard metric.
Ahmed +49 more
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Cubic Idempotence Preserver Problem in Hermitian Matrix Space
Journal of Harbin University of Science and TechnologyPreserver problems are the study of preserving maps of certain invariants on a given mathematical structure. In order to preserve the cubic idempotent of Hermitian matrix space, we study the image from the basis of 2 × 2-dimensional Hermitian matrix ...
ZHANG Haoran, XU Jinli
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IET Networks, EarlyView., 2023 We utilise a metaheuristic optimisation method, inspired by nature, called the Lévy‐flight firefly algorithm (LFA), to tackle the power regulation and user grouping in the NOMA systems. Abstract The non‐orthogonal multiple access strategies have shown promise to boost fifth generation and sixth generation wireless networks' spectral efficiency and ...
Zaid Albataineh +4 more
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