Results 31 to 40 of about 560 (182)
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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A multivariate Riesz basis of ReLU neural networks
Applied and Computational Harmonic AnalysisWe consider the trigonometric-like system of piecewise linear functions introduced recently by Daubechies, DeVore, Foucart, Hanin, and Petrova. We provide an alternative proof that this system forms a Riesz basis of $L_2([0,1])$ based on the Gershgorin theorem. We also generalize this system to higher dimensions $d>1$ by a construction, which avoids
Cornelia Schneider, Jan Vybíral
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Mathematical Methods in the Applied Sciences, EarlyView.ABSTRACT We develop a unified mathematical framework extending classical moment theory from discrete integer orders to a continuous spectrum of real orders f>0$$ f>0 $$, providing a systematic statistical characterization of complex systems exhibiting power‐law behavior.
Farrukh A. Chishtie
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Inverse problems for semilinear elliptic PDE with a general nonlinearity a(x,u)$a(x,u)$
Transactions of the London Mathematical Society, Volume 13, Issue 1, December 2026.Abstract This article studies the inverse problem of recovering a nonlinearity in an elliptic equation Δu+a(x,u)=0$\Delta u + a(x,u) = 0$ from boundary measurements of solutions. Previous results based on first‐order linearization achieve this under a sign condition on ∂ua(x,u)$\partial _u a(x,u)$, and results based on higher order linearization ...
David Johansson +2 more
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Riesz Basis in de Branges Spaces of Entire Functions
, 2022 In this paper we consider the problem of Riesz basis in de Branges spaces of entire functions H(E) with the condition that ϕ'(x) ≥ α > 0, where ϕ is the corresponding phase function. We are concerned with the sets of real numbers {λn} such that the normalized reproducing kernels k(λn, .)/||k(λn, .)|| satisfies the restricted isometry property, which
Al-Sa'di, Sa'ud, Obiedat, Hamed M.
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Mathematical Methods in the Applied Sciences, Volume 49, Issue 12, Page 14244-14265, August 2026.ABSTRACT In this second part of our series of papers, we develop an abstract framework suitable for de Rham complexes that depend on a parameter belonging to an arbitrary Banach space. Our primary focus is on spectral perturbation problems and the differentiability of eigenvalues with respect to perturbations of the involved parameters. As a byproduct,
Pier Domenico Lamberti +2 more
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Some relationship between G-frames and frames [PDF]
Sahand Communications in Mathematical Analysis, 2015 In this paper we proved that every g-Riesz basis for Hilbert space $H$ with respect to $K$ by adding a condition is a Riesz basis for Hilbert $B(K)$-module $B(H,K)$. This is an extension of [A. Askarizadeh,M. A.
Mehdi Rashidi-Kouchi, Akbar Nazari
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Mathematical Methods in the Applied Sciences, Volume 49, Issue 12, Page 14122-14148, August 2026.ABSTRACT This paper develops a mathematical framework for interpreting observations of solar inertial waves in an idealized setting. Under the assumption of purely toroidal linear waves on the sphere, the stream function of the flow satisfies a fourth‐order scalar equation.
Tram Thi Ngoc Nguyen +3 more
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Karpatsʹkì Matematičnì Publìkacìï, 2020 In this paper we continue to investigate the properties of the problem with nonlocal conditions, which are multipoint perturbations of mixed boundary conditions, started in the first part.
Ya.O. Baranetskij +3 more
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