Results 21 to 30 of about 450 (171)
Characterization of Compact Operators in Pre-Hilbert and Hilbert Spaces
Journal of Advances in Mathematics and Computer Science, 2022 The concept of a compact operator on a Hilbert space, H is an extension of the concept of a matrix acting on a finite-dimensional vector space. In Hilbert space, compact operators are precisely the closure of finite rank operators in the topology induced by the operator norm.
Aldril Wekesa Wanambisi +2 more
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Norm-Attainability and Range-Kernel Orthogonality of Elementary Operators
Communications in Advanced Mathematical Sciences, 2018 Various aspects of elementary operators have been characterized by many mathematicians. In this paper, we consider norm-attainability and orthogonality of these operators in Banach spaces.
Bernard Okelo
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Some Hilbert Space Characterizations and Banach Space Inequalities [PDF]
Mathematical Inequalities & Applications, 1998 Summary: It is well-known that if \(X\) is a normed linear space with dimension not less than three such that the radial projection from \(X\) onto the closed ball is nonexpansive, then \(X\) must be an inner product space. Using this fact, we are able to give a characterization of Hilbert spaces.
Kim, Tae-Hwa, Xu, Hong-Kun
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On a Characterization of Frames for Operators in Quaternionic Hilbert Spaces
Zurnal matematiceskoj fiziki, analiza, geometrii, 2022 Frames in quaternionic Hilbert space are discussed and studied in the paper. The authors introduce atomic systems in quaternionic Hilbert space and give a few analogous results in this regard. A result concerning \(K\)-frames in quaternionic Hilbert space is obtained.
Charfi, Salma, Ellouz, Hanen
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Closed embeddings of Hilbert spaces [PDF]
, 2010 Motivated by questions related to embeddings of homogeneous Sobolev spaces and to comparison of function spaces and operator ranges, we introduce the notion of closely embedded Hilbert spaces as an extension of that of continuous embedding of Hilbert ...
Gheondea, A. +3 more
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A characterization of the Gaussian distribution in a Hilbert space [PDF]
Pacific Journal of Mathematics, 1977 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
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Quantum-gate characterization in an extended Hilbert space [PDF]
Physical Review A, 2005 We describe an approach for characterizing the process of quantum gates using quantum process tomography, by first modeling them in an extended Hilbert space, which includes non-qubit degrees of freedom. To prevent unphysical processes from being predicted, present quantum process tomography procedures incorporate mathematical constraints, which make ...
Rohde, P. +3 more
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Generalized Phase (Norm) Retrieval Hermitian Matrices and $G$-frames [PDF]
Sahand Communications in Mathematical AnalysisThis paper is an analysis of the generalized phase (norm) retrieval problem, which aims to reconstruct a signal from its quadratic measurements. We provide some connections between phase (norm) retrieval $G$-frames and generalized phase (norm) retrieval ...
Fatemeh Shojaei +2 more
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A Nonlinear Characterization of Hilbert Spaces
Journal of Mathematical Analysis and Applications, 1996 The author has proved that a real Banach space \((X,|\cdot|)\) is a Hilbert space if and only if the duality map \(F\) of \(X\) maps line segments to convex sets.
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On Burkholder's Biconvex-Function Characterization of Hilbert Spaces [PDF]
Proceedings of the American Mathematical Society, 1993 Suppose that X {\mathbf {X}}
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