Results 61 to 70 of about 1,296 (214)

On solvability of the inverse problem for a fourth-order parabolic equation with a complex-valued coefficient

Қарағанды университетінің хабаршысы. Математика сериясы
In this paper, the inverse problem for a fourth-order parabolic equation with a variable complex-valued coefficient is studied by the method of separation of variables.
A.B. Imanbetova, A.A. Sarsenbi, B. Seilbekov   +2 more
doaj   +1 more source

Spectral Properties of Non-Self-Adjoint Perturbations for a Spectral Problem with Involution

Abstract and Applied Analysis, 2012
Full description of Riesz basis property for eigenfunctions of boundary value problems for first order differential equations with involutions is given.
Asylzat A. Kopzhassarova, Alexey L. Lukashov, Abdizhakhan M. Sarsenbi   +2 more
doaj   +1 more source

Nonlocal multipoint problem for a differential equation of $2n$-th order with operator coefficients

Karpatsʹkì Matematičnì Publìkacìï, 2021
In the article, the spectral properties of a multipoint problem for a differential operator equation of order $2n$ are studied. The operator of the problem has an infinite number of multiple eigenvalues.
Ya.O. Baranetskij, I.I. Demkiv, A.V. Solomko, O.M. Sus'   +3 more
doaj   +1 more source

The Steklov spectrum of spherical cylinders

Mathematika, Volume 72, Issue 2, April 2026.
Abstract The Steklov problem on a compact Lipschitz domain is to find harmonic functions on the interior whose outward normal derivative on the boundary is some multiple (eigenvalue) of their trace on the boundary. These eigenvalues form the Steklov spectrum of the domain.
Spencer Bullent
wiley   +1 more source

A review of a Riesz basis property for indefinite Sturm-Liouville problems [PDF]

Operators and Matrices, 2011
Consider the indefinite Sturm-Liouville problem−f ′′ = λrf, f(−1) = f(1) = 0 with an indefinite weight function r ∈ L[−1, 1] satisfying xr(x) > 0. A number of conditions for the so-called Riesz basis property are reviewed, i.e. conditions such that the eigenfunctions form a Ries basis of the Hilbert space L|r|[−1, 1].
Paul A. Binding, Andreas Fleige
openaire   +1 more source

Inner‐Layer Asymptotics in Partially Perforated Domains: Coupling Across Flat and Oscillating Interfaces

Mathematical Methods in the Applied Sciences, Volume 49, Issue 4, Page 3353-3384, 15 March 2026.
ABSTRACT The article examines a boundary‐value problem in a bounded domain Ωε$$ {\Omega}_{\varepsilon } $$ consisting of perforated and imperforate regions, with Neumann conditions prescribed at the boundaries of the perforations. Assuming the porous medium has symmetric, periodic structure with a small period ε$$ \varepsilon $$, we analyze the limit ...
Taras Melnyk
wiley   +1 more source

Semiclassical inequalities for Dirichlet and Neumann Laplacians on convex domains

Communications on Pure and Applied Mathematics, Volume 79, Issue 3, Page 762-822, March 2026.
Abstract We are interested in inequalities that bound the Riesz means of the eigenvalues of the Dirichlet and Neumann Laplacians in terms of their semiclassical counterpart. We show that the classical inequalities of Berezin–Li–Yau and Kröger, valid for Riesz exponents γ≥1$\gamma \ge 1$, extend to certain values γ<1$\gamma <1$, provided the underlying ...
Rupert L. Frank, Simon Larson
wiley   +1 more source

Potential trace inequalities via a Calderón‐type theorem

Journal of the London Mathematical Society, Volume 113, Issue 3, March 2026.
Abstract In this paper, we develop a general theoretical tool for the establishment of the boundedness of notoriously difficult operators (such as potentials) on certain specific types of rearrangement‐invariant function spaces from analogous properties of operators that are easier to handle (such as fractional maximal operators).
Zdeněk Mihula, Luboš Pick, Daniel Spector   +2 more
wiley   +1 more source

On the Generalized Bm-Riesz Difference Sequence Space and β-Property

Journal of Inequalities and Applications, 2009
We introduce the generalized Riesz difference sequence space rq(p,Bm) which is defined by rq(p,Bm)={x=(xk)∈w:Bmx∈rq(p)} where rq(p) is the Riesz sequence space defined by Altay and Başar.
Metin Ba&#351;arir, Mustafa Kayik&#231;i   +1 more
doaj   +1 more source

RVSIM: a feature similarity method for full-reference image quality assessment

EURASIP Journal on Image and Video Processing, 2018
Image quality assessment is an important topic in the field of digital image processing. In this study, a full-reference image quality assessment method called Riesz transform and Visual contrast sensitivity-based feature SIMilarity index (RVSIM) is ...
Guangyi Yang, Deshi Li, Fan Lu, Yue Liao, Wen Yang   +4 more
doaj   +1 more source