Results 51 to 60 of about 21,050 (203)

Analysis and construction of a family of refinable functions based on generalized Bernstein polynomials

Journal of Inequalities and Applications, 2016
In this paper, we construct a new family of refinable functions from generalized Bernstein polynomials, which include pseudo-splines of Type II. A comprehensive analysis of the refinable functions is carried out.
Ting Cheng, Xiaoyuan Yang
doaj   +1 more source

The nonlocal multipoint problem with Dirichlet-type conditions for an ordinary differential equation of even order with involution

Математичні Студії, 2020
The spectral properties of the nonself-adjoint problem with multipoint perturbations of the Dirichlet conditions for differential operator of order $2n$ with involution are investigated. The system of eigenfunctions of a multipoint problem is constructed.
Ya.O. Baranetskij, P.I. Kalenyuk, M. I. Kopach, A.V. Solomko   +3 more
doaj   +1 more source

Frames Containing a Riesz Basis and Preservation of This Property Under Perturbations

SIAM Journal on Mathematical Analysis, 1998
Aldroubi has shown how one can construct any frame $\gtu$ starting with one frame $\ftu $,using a bounded operator $U$ on $l^2(N)$. We study the overcompleteness of the frames in terms of properties of $U$. We also discuss perturbation of frames in the sense that two frames are ``close'' if a certain operator is compact.
Casazza, Peter G., Christensen, Ole
openaire   +3 more sources

A Choquet theory of Lipschitz‐free spaces

Proceedings of the London Mathematical Society, Volume 132, Issue 2, February 2026.
Abstract Let (M,d)$(M,d)$ be a complete metric space and let F(M)$\mathcal {F}({M})$ denote the Lipschitz‐free space over M$M$. We develop a ‘Choquet theory of Lipschitz‐free spaces’ that draws from the classical Choquet theory and the De Leeuw representation of elements of F(M)$\mathcal {F}({M})$ (and its bi‐dual) by positive Radon measures on βM ...
Richard J. Smith
wiley   +1 more source

Exponential Riesz bases, discrepancy of irrational rotations and BMO

, 2011
We study the basis property of systems of exponentials with frequencies belonging to 'simple quasicrystals'. We show that a diophantine condition is necessary and sufficient for such a system to be a Riesz basis in L^2 on a finite union of intervals. For
Kozma, Gady, Lev, Nir
core   +1 more source

Operator Characterizations and Some Properties of g-Frames on Hilbert Spaces

Journal of Function Spaces and Applications, 2013
Given the g-orthonormal basis for Hilbert space H, we characterize the g-frames, normalized tight g-frames, and g-Riesz bases in terms of the g-preframe operators.
Xunxiang Guo
doaj   +1 more source

On the lowest by $x$-variable terms influence on the spectral properties of dirichlet problem for the hyperbolic systems

Vestnik Samarskogo Gosudarstvennogo Tehničeskogo Universiteta. Seriâ: Fiziko-Matematičeskie Nauki, 2014
We made the comparison study and characterize the spectral properties of differential operators induced by the Dirichlet problem for the hyperbolic system without the lowest terms of the form $$ \cfrac{\partial^2{u^1}}{\partial{t}^2}+\cfrac{\partial^2{u ...
Olesya V Alexeeva, Vasiliy V Kornienko, Dmitriy V Kornienko   +2 more
doaj   +1 more source

ON THE INVERSE PROBLEM OF THE BITSADZE–SAMARSKII TYPE FOR A FRACTIONAL PARABOLIC EQUATION

Проблемы анализа, 2023
In this paper, the inverse problem of the Bitsadze–Samarsky type is studied for a fractional order equation with a Hadamard–Caputo fractional differentiation operator. The problem is solved using the spectral method.
R. R. Ashurov, B. J. Kadirkulov, B. Kh.Turmetov   +2 more
doaj   +1 more source

Decomposition theorem and Riesz basis for axisymmetric potentials in the right half-plane [PDF]

European Journal of Mathematics, 2015
The Weinstein equation with complex coefficients is the equation governing generalized axisymmetric potentials (GASP) which can be written as $L_m[u]= u+\left(m/x\right)\partial_x u =0$, where $m\in\mathbb{C}$. We generalize results known for $m\in\mathbb{R}$ to $m\in\mathbb{C}$.
Chaabi, Slah, Rigat, Stéphane
openaire   +2 more sources

Plank theorems and their applications: A survey

Bulletin of the London Mathematical Society, Volume 58, Issue 1, January 2026.
Abstract Plank problems concern the covering of convex bodies by planks in Euclidean space and are related to famous open problems in convex geometry. In this survey, we introduce plank problems and present surprising applications of plank theorems in various areas of mathematics.
William Verreault
wiley   +1 more source