Results 61 to 70 of about 488 (166)

Persistence of unknottedness of clean Lagrangian intersections

Journal of Topology, Volume 18, Issue 4, December 2025.
Abstract Let Q0$Q_0$ and Q1$Q_1$ be two Lagrangian spheres in a six‐dimensional symplectic manifold. Assume that Q0$Q_0$ and Q1$Q_1$ intersect cleanly along a circle that is unknotted in both Q0$Q_0$ and Q1$Q_1$. We prove that there is no nearby Hamiltonian isotopy of Q0$Q_0$ and Q1$Q_1$ to a pair of Lagrangian spheres meeting cleanly along a circle ...
Johan Asplund, Yin Li
wiley   +1 more source

Convergence Theorems and Measures of Noncompactness for Noncompact Urysohn Operators in Ideal Spaces

Journal of Integral Equations and Applications, 2004
The author considers the following nonlinear integral equation of Urysohn type \[ A(f)x(t):= \int_S f(t, s,x(s))\,ds,\quad t\in T, \] where the integral is in the Bochner sense. He establishes an estimate for the measure of noncompactness of the Urysohn operator and proves a convergence theorem for a sequence of simpler Urysohn operators which are ...
openaire   +2 more sources

A Note on the Existence and Optimal Control of Atangana–Baleanu Fractional Stochastic Integrodifferential System With Noninstantaneous Impulses

Optimal Control Applications and Methods, Volume 46, Issue 6, Page 2595-2611, November/December 2025.
Optimal Control of AB Caputo Fractional Stochastic Integrodifferential Control System with Noninstantaneous Impulses. ABSTRACT This study is concerned with the existence of mild solution and optimal control for the Atangana–Baleanu fractional stochastic integrodifferential system with noninstantaneous impulses in Hilbert spaces. We verify the existence
Murugesan Johnson, Velusamy Vijayakumar, Kiwoon Kwon   +2 more
wiley   +1 more source

Existence of solutions of infinite systems of nonlinear Volterra integral equations on a Fréchet space

پژوهش‌های ریاضی, 2021
In this paper, we introduce a Fréchet space  and define a measure of noncompactness on it.  For credit and the application to our theorems, in the application section of this paper, we present a theorem which shows the existence of solution of infinite ...
Hogat Allah Amiri kayvanloo, Mahnaz Khanehgir, Reza Allahyari   +2 more
doaj  

Measures of noncompactness on the standard hilbert C*-module

Filomat, 2019
We define a measure of noncompactness ? on the standard Hilbert C*-module l2(A) over a unital C*-algebra, such that ?(E) = 0 if and only if E is A-precompact (i.e. it is ?-close to a finitely generated projective submodule for any ? > 0) and derive its properties.
Dragoljub Keckic, Zlatko Lazovic
openaire   +4 more sources

Optimal Control Strategies and Continuous Dependence for Stochastic Hilfer Fractional Systems With Delay: A Volterra‐Fredholm Integro‐Differential Approach

Optimal Control Applications and Methods, Volume 46, Issue 6, Page 2708-2726, November/December 2025.
The graphical abstract highlights our research on Sobolev Hilfer fractional Volterra‐Fredholm integro‐differential (SHFVFI) control problems for 1<ϱ<2$$ 1<\varrho <2 $$. We begin with the Hilfer fractional derivative (HFD) of order (1,2) in Sobolev type, which leads to Volterra‐Fredholm integro‐differential equations.
Marimuthu Mohan Raja, V. Vijayakumar, Chun‐Wei Tsai, Kalyana Chakravarthy Veluvolu   +3 more
wiley   +1 more source

Solvability of second order linear differential equations in the sequence space n(ϕ) $n(\phi)$

Advances in Difference Equations, 2018
We apply the concept of measure of noncompactness to study the existence of solution of second order differential equations with initial conditions in the sequence space n(ϕ) $n(\phi)$.
Abdullah Alotaibi, M. Mursaleen, Badriah A. S. Alamri   +2 more
doaj   +1 more source

Semigroups of operators and measures of noncompactness

Journal of Functional Analysis, 1971
AbstractIt is observed that the perturbation class of an open semigroup in a Banach algebra is a closed two-sided ideal. Certain seminorms on the algebra of bounded operators are introduced; these seminorms induce norms on the quotient algebra modulo the ideal of compact operators.
Lebow, Arnold, Schechter, Martin
openaire   +1 more source

The three‐dimensional Seiberg–Witten equations for 3/2$3/2$‐spinors: A compactness theorem

Mathematische Nachrichten, Volume 298, Issue 10, Page 3331-3375, October 2025.
Abstract The Rarita‐Schwinger–Seiberg‐Witten (RS–SW) equations are defined similarly to the classical Seiberg–Witten equations, where a geometric non–Dirac‐type operator replaces the Dirac operator called the Rarita–Schwinger operator. In dimension 4, the RS–SW equation was first considered by the second author (Nguyen [J. Geom. Anal. 33(2023), no. 10,
Ahmad Reza Haj Saeedi Sadegh, Minh Lam Nguyen   +1 more
wiley   +1 more source

Some Properties of Measures of Noncompactness in Paranormed Spaces [PDF]

Proceedings of the American Mathematical Society, 1988
This paper presents new properties of important measures of noncompactness in paranormed spaces. Using these properties some fixed point theorems for multivalued mappings in general topological vector spaces are obtained in a straightforward way.
openaire   +2 more sources