27 citations · 122 across the 18 of their papers we have counts for
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Weighted finite Fourier transform operator: Uniform approximations of the eigenfunctions, eigenvalues decay and behaviour
Abderrazek Karoui, Ahmed Souabni
In this paper, we first give two uniform asymptotic approximations of the eigenfunctions of the weighted finite Fourier transform operator, defined by ${\displaystyle \mathcal F_c^…
Approximations in Sobolev Spaces by Prolate Spheroidal Wave Functions
Aline Bonami, Abderrazek Karoui
Recently, there is a growing interest in the spectral approximation by the Prolate Spheroidal Wave Functions (PSWFs) This is due to the promising new contributio…
Spectral Decay of Time and Frequency Limiting Operator
Aline Bonami, Abderrazek Karoui
For fixed the Prolate Spheroidal Wave Functions (PSWFs) form a basis with remarkable properties for the space of band-limited functions with bandwidth . They hav…
Generalized Prolate Spheroidal Wave Functions: Spectral Analysis and Approximation of Almost Band-limited Functions
Abderrazek Karoui, Ahmed Souabni
In this work, we first give various explicit and local estimates of the eigenfunctions of a perturbed Jacobi differential operator. These eigenfunctions generalize the famous class…
The approximation of almost time and band limited functions by their expansion in some orthogonal polynomials bases
Philippe Jaming, Abderrazek Karoui, Susanna Spektor
The aim of this paper is to investigate the quality of approximation of almost time and almost band-limited functions by its expansion in three classical orthogonal polynomials bas…