Results 61 to 70 of about 714 (196)
Pseudobosons, Riesz bases, and coherent states [PDF]
Journal of Mathematical Physics, 2010 In a recent paper, Trifonov suggested a possible explicit model of a PT-symmetric system based on a modification of the canonical commutation relation. Although being rather intriguing, in his treatment many mathematical aspects of the model have just been neglected, making most of the results of that paper purely formal.
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p-Riesz bases in quasi shift invariant spaces [PDF]
, 2018 Let 1 ≤ p < ∞ and let ψ ∈ Lp(R d ). We study p−Riesz bases of quasi shift invariant spaces Vp(ψ; Y )
De Carli, Laura +3 more
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Comparative Study Between Frames and Riesz Bases [PDF]
, 2017 Los frames son una herramienta conveniente y flexible para obtener expansiones en los espacios de Hilbert de forma similar como aquellas vía bases ortonormales.
Gómez Jiménez, Angela Nohelia
core
Karpatsʹkì Matematičnì Publìkacìï, 2018 We study a problem with periodic boundary conditions for a $2n$-order differential equation whose coefficients are non-self-adjoint operators. It is established that the operator of the problem has two invariant subspaces generated by the involution ...
Ya.O. Baranetskij +3 more
doaj +1 more source
Finite Element Approximation for a Reformulation of a 3D Fluid–2D Plate Interaction System
Numerical Methods for Partial Differential Equations, Volume 42, Issue 4, July 2026.ABSTRACT We study a finite element approximation of a coupled fluid‐structure interaction consisting of a three‐dimensional incompressible viscous fluid governed by the unsteady Stokes equations and a two‐dimensional elastic plate. To avoid the use of H2−$$ {H}^2- $$conforming or nonconforming ℙ2$$ {\mathbb{P}}_2 $$‐Morley plate elements, the fourth ...
Lander Besabe, Hyesuk Lee
wiley +1 more source
On a Characterization of Riesz Bases via Biorthogonal Sequences [PDF]
Journal of Fourier Analysis and Applications, 2020 AbstractIt is well known that a sequence in a Hilbert space is a Riesz basis if and only if it is a complete Bessel sequence with biorthogonal sequence which is also a complete Bessel sequence. Here we prove that the completeness of one (any one) of the biorthogonal sequences can be removed from the characterization.
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Inducing Riesz Bases in $L^2$ via Composition Operators [PDF]
Let Ch be a composition operator mapping L2(1) into L2(2) for some open sets1, 2 ⊆ Rn. We characterize the mappings h that transform Riesz bases of L2(1)into Riesz bases of L2(2).
Saleh, Yahya, Iske, Armin
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A general theory of inverse welfare functions
Theoretical Economics, Volume 21, Issue 3, Page 973-1018, July 2026.This paper develops a general theory to recover the inverse welfare function that rationalizes a given tax schedule as optimal. Our theory allows for complex environments including the presence of multidimensional tax schedules, bunching/jumping behavior, optimization frictions, general equilibrium effects, and externalities.
Katy Bergstrom, William Dodds
wiley +1 more source
Riesz bases of exponentials and the Bohr topology
Proceedings of the American Mathematical Society, 2021 We provide a necessary and sufficient condition to ensure that a multi-tile Ω
Cabrelli, Carlos +2 more
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The Canadian Journal of Chemical Engineering, Volume 104, Issue 6, Page 3018-3037, June 2026.Abstract We develop a delay‐aware estimation and control framework for a non‐isothermal axial dispersion tubular reactor modelled as a coupled parabolic‐hyperbolic PDE system with recycle‐induced state delay. The infinite‐dimensional dynamics are preserved without spatial discretization by representing the delay as a transport PDE and adopting a late ...
Behrad Moadeli, Stevan Dubljevic
wiley +1 more source