Results 41 to 50 of about 614,326 (146)

Khatri-Rao Products for Operator Matrices Acting on the Direct Sum of Hilbert Spaces

Journal of Mathematics, 2016
We introduce the notion of Khatri-Rao product for operator matrices acting on the direct sum of Hilbert spaces. This notion generalizes the tensor product and Hadamard product of operators and the Khatri-Rao product of matrices.
Arnon Ploymukda, Pattrawut Chansangiam
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Direct sum decompositions and indecomposable TQFTs [PDF]

Journal of Mathematical Physics, 1995
The decomposition of an arbitrary axiomatic topological quantum field theory or TQFT into indecomposable theories is given. In particular, unitary TQFTs in arbitrary dimensions are shown to decompose into a sum of theories in which the Hilbert space of the sphere is one-dimensional, and indecomposable two-dimensional theories are classified.
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Systematics of U-spin sum rules for systems with direct sums

Journal of High Energy Physics
A rich mathematical structure underlying flavor sum rules has been discovered recently. In this work, we extend these findings to systems with a direct sum of representations. We prove several results for the general case.
Margarita Gavrilova, Stefan Schacht
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Coerciveness and isomorphism of discontinuous Sturm-Liouville problems with transmission conditions

Journal of New Results in Science
This study investigates a discontinuous Sturm-Liouville boundary value problem(BVP) on two intervals with functionals and transmission conditions in the direct sum ofSobolev spaces. Moreover, it presents the differential operator generated by the problem
Murat Küçük, Mustafa Kandemir
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Quasi-Projective Covers and Direct Sums [PDF]

Proceedings of the American Mathematical Society, 1970
In this paper R R denotes an associative ring with an identity, and all modules are unital left R R -modules. It is shown that the existence of a quasi-projective cover for each module implies that each module has a projective cover. By a similar technique the following statements are shown to be equivalent: 1.
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Spectrum of the direct sum of operators

Electronic Journal of Differential Equations, 2012
We study the connection between spectral properties of direct the sum of operators in the direct sum of Hilbert spaces and its coordinate operators.
Elif Otkun Cevik, Zameddin I. Ismailov
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Direct Sum Decomposition of the Integers [PDF]

Tokyo Journal of Mathematics, 1995
Denote by \(\mathbb{Z}(\mathbb{N})\) the set of all integers (all positive integers). If \(A,B\subseteq\mathbb{Z}\), then we put \(A+B= \{a+b: a\in A, b\in B\}\), \(A-B= \{a-b:a\in A, b\in B\}\). If \(A+B=\mathbb{Z}\) and every \(z\in\mathbb{Z}\) can be uniquely expressed in the form \(z=a+b\), then we write \(A\oplus B=\mathbb{Z}\) and \(\mathbb{Z ...
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An abstract approach to some spectral problems of direct sum differential operators

Electronic Journal of Differential Equations, 2003
In this paper, we study the common spectral properties of abstract self-adjoint direct sum operators, considered in a direct sum Hilbert space. Applications of such operators arise in the modelling of processes of multi-particle quantum mechanics ...
Maksim S. Sokolov
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Relative injectivity and CS-modules

International Journal of Mathematics and Mathematical Sciences, 1994
In this paper we show that a direct decomposition of modules M⊕N, with N homologically independent to the injective hull of M, is a CS-module if and only if N is injective relative to M and both of M and N are CS-modules. As an application, we prove that
Mahmoud Ahmed Kamal
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On totally projective QTAG-modules

Journal of Taibah University for Science, 2019
A module M over an associative ring R with unity is a QTAG-module if every finitely generated submodule of any homomorphic image of M is a direct sum of uniserial modules.
Fahad Sikander, Tanveer Fatima
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