Results 61 to 70 of about 450 (171)
On the adjoint of Hilbert space operators
, 2018 In general, it is a non-trivial task to determine the adjoint (Formula presented.) of an unbounded operator S acting between two Hilbert spaces. We provide necessary and sufficient conditions for a given operator T to be identical with (Formula presented.
Sebestyén, Z +3 more
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A characterization of Gaussian law in Hilbert space
Aequationes Mathematicae, 1990 Let \({\mathcal H}\) be a real separable Hilbert space and let X and Y be independent random variables taking values in \({\mathcal H}\). The aim of the paper is to prove that \(X+Y\) and X-Y are independent if and only if each of X and Y is Gaussian. The proof is based on solving a functional equation satisfied by the characteristic functions of X and
openaire +1 more source
Least-squares solutions of multi-valued linear operator equations in Hilbert spaces
, 1983 Let M be a linear manifold in H1 ⊕ H2, where H1, and H2 are Hilbert spaces. Two notions of least-squares solutions for the multi-valued linear operator equation (inclusion) y ϵ M(x) are introduced and investigated. The main results include (i) equivalent
Nashed, M.Zuhair, Lee, Sung J
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Geometry in preduals of spaces of 2-homogeneous polynomials on Hilbert spaces
, 2009 Let H be a (real or complex) Hilbert space. Using spectral theory and properties of the Schatten–Von Neumann operators, we prove that every symmetric tensor of unit norm in HoH is an infinite absolute convex combination of points of the form xox with x ...
Garcia, D. +5 more
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Compact and finite rank perturbations of linear relations in Hilbert spaces [PDF]
, 2007 For closed linear operators or relations A and B acting between Hilbert spaces H and K the concepts of compact and finite rank perturbations are introduced with the help of the orthogonal projections PA and PB in H©K onto A and B.
Behrndt, Jussi +3 more
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New extremal characterizations of generalized inverses of linear operators
, 1981 In 1956, R. Penrose studied best-approximate solutions of the matrix equation AX = B. He proved that A+B (where A+ is the Moore-Penrose inverse) is the unique matrix of minimal Frobenius norm among all matrices which minimize the Frobenius norm of AX − B.
Engl, Heinz W, Nashed, M.Z
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Certain Characterizations of Tight Gabor Frames on Local Fields
, 2015 Gabor systems are generated by modulations and translations of a single function. Many researchers studied Gabor frames in Hilbert spaces. The concepts Gabor frames on local fields, first introduced by Li and Jiang.
Abdullah
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Characterizing R-duality in Banach spaces
, 2013 R-duals of certain sequences in Hilbert spaces were introduced by Casazza, Kutyniok and Lammers in 2004 and later generalized to Banach spaces by Xiao and Zhu.
Christensen, Ole +2 more
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Extending Hilbert-Schmidt Independence Criterion for Testing Conditional Independence. [PDF]
Entropy (Basel), 2023 Zhang B, Suzuki J.
europepmc +1 more source
Characterization of Hilbert spaces by the strong law of large numbers
Hilbert spaces are characterized through the validity of the strong law of large numbers. Other characterizations of Hilbert spaces are also given at the same time in this note.law of large numbers covariance operators nuclear operators relative ...
Kawabe, Jun
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