Results 21 to 30 of about 296 (136)

On the Existence of Solutions of Dynamic Equations on Time Scales in Banach Spaces

open access: yesMathematical Methods in the Applied Sciences, Volume 49, Issue 13, Page 15358-15384, 15 September 2026.
ABSTRACT In this paper we address the question of solvability of dynamic equations on time scales in Banach spaces. In particular, our main theorem extends the result for classical differential equations in Banach spaces of Banaś and Goebel established in [5], to an arbitrary time scale.
Dušan Oberta
wiley   +1 more source

A Unified Approach to Solvability and Stability of Multipoint BVPs for Langevin and Sturm–Liouville Equations with CH–Fractional Derivatives and Impulses via Coincidence Theory

open access: yesFractal and Fractional
The Langevin equation is a model for describing Brownian motion, while the Sturm–Liouville equation is an important mechanical model. This paper focuses on the solvability and stability of nonlinear impulsive Langevin and Sturm–Liouville equations with ...
Kaihong Zhao, Juqing Liu, Xiaojun Lv
doaj   +1 more source

Stable factorization of the Calderón problem via the Born approximation

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 6, June 2026.
Abstract In this article, we prove the existence of the Born approximation in the context of the radial Calderón problem for Schrödinger operators. The Born approximation naturally appears as the linear component of a factorization of the Calderón problem; we show that the nonlinear part, obtaining the potential from the Born approximation, enjoys ...
Thierry Daudé   +3 more
wiley   +1 more source

Internal Wave Characteristics in the Andaman Sea: New Insights From SWOT Observations

open access: yesGeophysical Research Letters, Volume 53, Issue 10, 28 May 2026.
Abstract High‐resolution, repeat‐pass Sea Surface Height Anomaly (SSHA) observations from the Surface Water and Ocean Topography (SWOT) satellite are used to investigate Internal Solitary Waves (ISW) in the Andaman Sea over a one‐year period starting in July 2023. SWOT captured surface signatures of high‐amplitude ISW, with SSHA exceeding 20 cm.
Anup Kumar Mandal   +7 more
wiley   +1 more source

Fundamental Spectral Theory of Fractional Singular Sturm-Liouville Operator

open access: yesJournal of Function Spaces and Applications, 2013
We give the theory of spectral properties for eigenvalues and eigenfunctions of Bessel type of fractional singular Sturm-Liouville problem. We show that the eigenvalues and eigenfunctions of the problem are real and orthogonal, respectively. Furthermore,
Erdal Bas
doaj   +1 more source

Effect of Field Line Torsion on the Polarization of ULF Waves

open access: yesJournal of Geophysical Research: Space Physics, Volume 131, Issue 5, May 2026.
Abstract In this paper we suggest a simple modification of the dipole magnetic field which introduces field‐aligned currents and torsion to the field lines. The resulting field lines are not contained in the meridional planes and have resemblance to the geomagnetic field lines in the dawn and dusk flanks of the magnetosphere. We analyze polarization of
K. Kabin, A. W. Degeling, R. Rankin
wiley   +1 more source

Maximally dissipative and self‐adjoint extensions of K$K$‐invariant operators

open access: yesBulletin of the London Mathematical Society, Volume 58, Issue 5, May 2026.
Abstract We introduce the notion of K$K$‐invariant operators, S$S$, in a Hilbert space, with respect to a bounded and boundedly invertible operator K$K$ defined via K∗SK=S$K^*SK=S$. Conditions such that self‐adjoint and maximally dissipative extensions of K$K$‐invariant symmetric operators are also K$K$‐invariant are investigated.
Christoph Fischbacher   +2 more
wiley   +1 more source

The Linearized Korteweg–de Vries Equation on the Line With Metric Graph Defects

open access: yesStudies in Applied Mathematics, Volume 156, Issue 4, April 2026.
ABSTRACT We study the small‐amplitude linearization of the Korteweg–de Vries equation on the line with a local defect scattering waves represented by a metric graph domain adjoined at one point. For a representative collection of examples, we derive explicit solution formulas expressed as contour integrals and obtain existence and unicity results for ...
D. A. Smith
wiley   +1 more source

Operator-pencil treatment of multi-interval Sturm-Liouville equation with boundary-transmission conditions

open access: yesҚарағанды университетінің хабаршысы. Математика сериясы
This paper is devoted to a new type of boundary-value problems for Sturm-Liouville equations defined on three disjoint intervals (−π,−π+d),(−π+d,π−d) and (π−d,π) together with eigenparameter dependent boundary conditions and with additional transmission
H. Olǧar, F. Muhtarov, O. Mukhtarov
doaj   +1 more source

Multiple front and pulse solutions in spatially periodic systems

open access: yesJournal of the London Mathematical Society, Volume 113, Issue 4, April 2026.
Abstract In this paper, we develop a comprehensive mathematical toolbox for the construction and spectral stability analysis of stationary multiple front and pulse solutions to general semilinear evolution problems on the real line with spatially periodic coefficients.
Lukas Bengel, Björn de Rijk
wiley   +1 more source

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