Results 11 to 20 of about 539 (137)
Some New Notions of Bases for the Range of Operators in Hilbert Spaces [PDF]
Sahand Communications in Mathematical AnalysisThis paper is devoted to introduce a new concept of bases for the range of the operator $K$. Actually, we consider controlled $K$-orthonormal and controlled $K$-Riesz bases which are a generalization of ordinary bases in Hilbert spaces. In the sequel, we
Hessam Hosseinnezhad
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An overview of the null-field method. II: Convergence and numerical stability
Physics Open, 2020 In this paper we provide an analysis of the convergence and numerical stability of the null-field method with discrete sources. We show that (i) if the null-field scheme is numerically stable then we can decide whether or not convergence can be achieved;
Adrian Doicu, Michael I. Mishchenko
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Riesz basis property of Timoshenko beams with boundary feedback control
International Journal of Mathematics and Mathematical Sciences, 2003 A Timoshenko beam equation with boundary feedback control is considered. By an abstract result on the Riesz basis generation for the discrete operators in the Hilbert spaces, we show that the closed-loop system is a Riesz system, that is, the sequence of
De-Xing Feng +2 more
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Riesz Basicity for General Systems of Functions
Journal of Function Spaces, 2014 In this paper we find the general conditions for a complete biorthogonal conjugate system to form a Riesz basis. We show that if a complete biorthogonal conjugate system is uniformly bounded and its coefficient space is solid, then the system forms a ...
A. M. Sarsenbi, P. A. Terekhin
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A New Approach to Continuous Riesz Bases [PDF]
Journal of Sciences, Islamic Republic of Iran, 2013 This paper deals with continuous frames and continuous Riesz bases. We introduce continuous Riesz bases and give some equivalent conditions for a continuous frame to be a continuous Riesz basis.
A.A. Arefijamaal +3 more
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Comment on “Continuous g-Frame in Hilbert -Modules”
Abstract and Applied Analysis, 2013 The continuous g-frames in Hilbert -modules were introduced and investigated by Kouchi and Nazari (2011). They also studied the continuous g-Riesz basis and a characterization for it was presented by using the synthesis operator. However, we found that
Zhong-Qi Xiang
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Riesz bases and positive operators on Hilbert space
International Journal of Mathematics and Mathematical Sciences, 2003 It is shown that a normalized Riesz basis for a Hilbert space H (i.e., the isomorphic image of an orthonormal basis in H) induces in a natural way a new, but equivalent, inner product on H in which it is an orthonormal basis, thereby extending the sense ...
James R. Holub
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Journal of Applied Mathematics, 2013 We introduce the modular continuous g-Riesz basis to improve one existing result for continuous g-Riesz basis in Hilbert -modules, and then we study the equivalency relations between continuous g-frames in Hilbert -modules, and, in particular, we obtain ...
Zhong-Qi Xiang
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Karpatsʹkì Matematičnì Publìkacìï, 2018 In this article, we investigate a problem with nonlocal boundary conditions which are perturbations of antiperiodical conditions in bounded $m$-dimensional parallelepiped using Fourier method. We describe properties of a transformation operator $R:L_2(G)
Ya.O. Baranetskij +3 more
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ON COMPLETE RIESZ–FISCHER SEQUENCES IN A HILBERT SPACE
Проблемы анализаWe prove that if {𝑓_𝑛}^\infty_{n=1} is a complete Riesz–Fischer sequence in a separable Hilbert space 𝐻, then 𝑇 :={𝑓 \in 𝐻 : \Sum ...
Elias Zikkos
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