Results 71 to 80 of about 269 (133)

Compactness via Hausdorff measure of non-compactness and some properties on Tetranacci sequence spaces

Dera Natung Government College Research Journal
The characterization of compact operators on BK-spaces, which is the basis of this research, makes use of the Hausdorff measure of non-compactness. In this study, the compactness criteria of matrix operators defined on BK-spaces $\ell_p(\mathcal{T})$ and
Sezer Erdem, Serkan Demiriz
doaj   +1 more source

Strong subgroup recurrence and the Nevo–Stuck–Zimmer theorem

Proceedings of the London Mathematical Society, Volume 130, Issue 6, June 2025.
Abstract Let Γ$\Gamma$ be a countable group and Sub(Γ)$\mathrm{Sub}(\Gamma)$ its Chabauty space, namely, the compact Γ$\Gamma$‐space consisting of all subgroups of Γ$\Gamma$. We call a subgroup Δ∈Sub(Γ)$\Delta \in \mathrm{Sub}(\Gamma)$ a boomerang subgroup if for every γ∈Γ$\gamma \in \Gamma$, γniΔγ−ni→Δ$\gamma ^{n_i} \Delta \gamma ^{-n_i} \rightarrow ...
Yair Glasner, Waltraud Lederle
wiley   +1 more source

On Shehtman's two problems

Journal of the London Mathematical Society, Volume 111, Issue 3, March 2025.
Abstract We provide partial solutions to two problems posed by Shehtman concerning the modal logic of the Čech–Stone compactification of an ordinal space. We use the Continuum Hypothesis to give a finite axiomatization of the modal logic of β(ω2)$\beta (\omega ^2)$, thus resolving Shehtman's first problem for n=2$n=2$. We also characterize modal logics
Guram Bezhanishvili, Nick Bezhanishvili, Joel Lucero‐Bryan, Jan van Mill   +3 more
wiley   +1 more source

The Mumford conjecture (after Bianchi)

Journal of Topology, Volume 18, Issue 1, March 2025.
Abstract We give a self‐contained and streamlined rendition of Andrea Bianchi's recent proof of the Mumford conjecture using moduli spaces of branched covers.
Ronno Das, Dan Petersen
wiley   +1 more source

Existence of Mild Solutions for a Semilinear Integrodifferential Equation with Nonlocal Initial Conditions

Abstract and Applied Analysis, 2012
Using Hausdorff measure of noncompactness and a fixed-point argument we prove the existence of mild solutions for the semilinear integrodifferential equation subject to nonlocal initial conditions u′(t)=Au(t)+∫0tB(t-s)u(s)ds+f(t,u(t)), t∈[0,1], u(0)=g(u),
Carlos Lizama, Juan C. Pozo
doaj   +1 more source

Applications of measures of noncompactness to infinite system of fractional differential equations

, 2017
In this paper, we discuss few existence result for solution of an infinite system of fractional differential equations of order ?(1 < ? < 2), with three point boundary value problem in the interval [0, T].
Syed Rizvi, Bilal Bilalov, Mohammad Mursaleen   +2 more
core   +1 more source

Sequence spaces and measures of noncompactness with applications to differential and integral equations

, 2014
This book deals with the study of sequence spaces, matrix transformations, measures of noncompactness and their various applications. The notion of measure of noncompactness is one of the most useful ones available and has many applications.
Mursaleen, Mohammad, Banaś, Józef
core   +1 more source

On solvability of the impulsive Cauchy problem for integro-differential inclusions with non-densely defined operators. [PDF]

Philos Trans A Math Phys Eng Sci, 2021
Benedetti I, Obukhovskii V, Taddei V.
europepmc   +1 more source

Measures of Noncircularity and Fixed Points of Contractive Multifunctions

Fixed Point Theory and Applications, 2010
In analogy to the Eisenfeld-Lakshmikantham measure of nonconvexity and the Hausdorff measure of noncompactness, we introduce two mutually equivalent measures of noncircularity for Banach spaces satisfying a Cantor type property, and apply them to ...
Marrero Isabel
doaj  

On a unified study of relative Chebyshev radii and Hausdorff measures of noncompactness

, 2004
The paper is concerned with the notion of the Lifschitz modulus and its relationship with both relative Chebyshev radii and Hausdorff measures of noncompactness.
Espínola García, Rafael, Wisnicki, Andrzej, Wosko, Jacek   +2 more
openaire   +3 more sources