Results 71 to 80 of about 1,106 (205)

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

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  

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

Uniqueness on average of large isoperimetric sets in noncompact manifolds with nonnegative Ricci curvature

Communications on Pure and Applied Mathematics, Volume 78, Issue 9, Page 1656-1702, September 2025.
Abstract Let (Mn,g)$(M^n,g)$ be a complete Riemannian manifold which is not isometric to Rn$\mathbb {R}^n$, has nonnegative Ricci curvature, Euclidean volume growth, and quadratic Riemann curvature decay. We prove that there exists a set G⊂(0,∞)$\mathcal {G}\subset (0,\infty)$ with density 1 at infinity such that for every V∈G$V\in \mathcal {G}$ there ...
Gioacchino Antonelli, Marco Pozzetta, Daniele Semola   +2 more
wiley   +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

Measures of noncompactness in some new lacunary difference sequence\n spaces [PDF]

, 2015
Ekrem Savaş, Stuti Borgohain
openalex   +2 more sources

Tripled Fixed Points and Existence Study to a Tripled Impulsive Fractional Differential System via Measures of Noncompactness [PDF]

, 2021
Sina Etemad, Mohammed M. Matar, Maria Alessandra Ragusa, Shahram Rezapour   +3 more
openalex   +1 more source

Controllability problem for fractional impulsive integrodifferential evolution systems of mixed type with the measure of noncompactness

Results in Nonlinear Analysis, 2020
We consider the controllability problem for a class of fractional impulsive evolution systems of mixed type in an infinite dimensional Banach space. The existence of mild solutions and controllability results are discussed by a new estimation technique
Duraisamy Senthil Raja, Ponnusamy Sundararajan, Kulandhaivel Karthikeyan
doaj  

Solvability of an infinite system of $ n $-th order differential equations in a paranormed sequence space and its numerical solution

AIMS Mathematics
In this paper, we introduce a ball measure of noncompactness in the Banach sequence space $ bv_q $ $ (1\leq q < \infty) $ containing the space $ l_q $.
Hojjatollah Amiri Kayvanloo, Mohammad Mehrabinezhad, Mahnaz Khanehgir, Reza Allahyari, Mohammad Mursaleen   +4 more
doaj   +1 more source

Existence of solutions for some classes of integro-differential equations via measure of noncompactness

Electronic Journal of Qualitative Theory of Differential Equations, 2015
In this present paper, we introduce a new measure of noncompactness on the space consisting of all real functions which are $n$ times bounded and continuously differentiable on $\mathbb{R}_+$.
Reza Allahyari, Reza Arab, Ali Shole Haghighi   +2 more
doaj   +1 more source