Results 111 to 120 of about 714 (196)

Riesz bases of eigenfunctions of 1D Dirac operator with strictly regular boundary condition [PDF]

, 2011
One dimensional Dirac operators [equation] considered with L2-potentials [equation] ; and subject to regular boundary conditions bc have discrete spectrum.
Duman, Hatice
core  

Riesz bases in quaternionic Hilbert spaces

, 2019
10 Pages.
Sharma, S. K., Virender, Kaushik, S. K.
openaire   +2 more sources

Principal non-singularity of Fourier matrices on Zp×Zq ${\mathbb{Z}}_{p}{\times}{\mathbb{Z}}_{q}$ and Z2k×Zq ${\mathbb{Z}}_{2}^{k}{\times}{\mathbb{Z}}_{q}$

Demonstratio Mathematica
Let F n be the n × n Fourier matrix on the cyclic group Zn ${\mathbb{Z}}_{n}$ , a renowned theorem of Chebotarëv asserts that all minors in F n for prime n are non-zero.
Zhou Weiqi
doaj   +1 more source

Hierarchical Riesz Bases for H s(\Omega), [PDF]

, 2003
1 Introduction This paper deals with the construction of Riesz bases for the Sobolov spaces Hs(\Omega) for s 2 (1, 52) on arbitrary polygonal domains \Omega ae R2.
Oleg Davydov, Rob Stevenson
core  

On various Riesz-dual sequences for Schauder frames. [PDF]

Heliyon, 2020
Neisi AR, Asgari MS.
europepmc   +1 more source

Sampling, interpolation and Riesz bases in small Fock spaces [PDF]

, 2015
International audienceWe give a complete description of Riesz bases of reproducing kernels in small Fock spaces. This characterization is in the spirit of the well known Kadets--Ingham 1/4 theorem for Paley--Wiener spaces.
Kellay, Karim, Baranov, Anton, Dumont, André, Hartmann, Andreas   +3 more
core  

Sparse Machine Learning in Banach Spaces. [PDF]

Appl Numer Math, 2023
Xu Y.
europepmc   +1 more source

Construction of wavelet dictionaries for ECG modeling. [PDF]

MethodsX, 2021
Černá D, Rebollo-Neira L.
europepmc   +1 more source

Riesz bases for p-subordinate perturbations of normal operators

Journal of Functional Analysis, 2010
For p-subordinate perturbations of unbounded normal operators, the change of the spectrum is studied and spectral criteria for the existence of a Riesz basis with parentheses of root vectors are established. A Riesz basis without parentheses is obtained under an additional a priori assumption on the spectrum of the perturbed operator.
openaire   +3 more sources

Complete interpolation vs. Riesz bases of reproducing kernels [PDF]

, 2014
In the study of Hilbert spaces of analytic functions, it is noticed that complete interpolating sequences and Riesz bases of reproducing kernels are dual notions. In this work we make this duality explicit by identifying sequences of complex numbers with
Cowell, Simon R., Poulin, Philippe
core