Results 21 to 30 of about 199 (164)

Nonlocal boundary value problems for second-order nonlinear Hahn integro-difference equations with integral boundary conditions

Advances in Difference Equations, 2017
In this paper, we study a boundary value problem for second-order nonlinear Hahn integro-difference equations with nonlocal integral boundary conditions. Our problem contains two Hahn difference operators and a Hahn integral. The existence and uniqueness
Umaphon Sriphanomwan, Jessada Tariboon, Nichaphat Patanarapeelert, Sotiris K Ntouyas, Thanin Sitthiwirattham   +4 more
doaj   +1 more source

A characterization of random approximations

International Journal of Mathematics and Mathematical Sciences, 1999
By using Hahn-Banach theorem, a characterization of random approximations is obtained.
Ismat Beg
doaj   +1 more source

Markov Moment Problem and Sandwich Conditions on Bounded Linear Operators in Terms of Quadratic Forms

Mathematics, 2022
As is well-known, unlike the one-dimensional case, there exist nonnegative polynomials in several real variables that are not sums of squares. First, we briefly review a method of approximating any real-valued nonnegative continuous compactly supported ...
Octav Olteanu
doaj   +1 more source

Note on the Hahn-Banach Theorem in a Partially Ordered Vector Space

Journal of Applied Mathematics, 2013
Using a fixed point theorem in a partially ordered set, we give a new proof of the Hahn-Banach theorem in the case where the range space is a partially ordered vector space.
Toshiharu Kawasaki, Masashi Toyoda, Toshikazu Watanabe   +2 more
doaj   +1 more source

The Hahn-Banach Extension Theorem for Fuzzy Normed Spaces Revisited

Abstract and Applied Analysis, 2014
This paper deals with fuzzy normed spaces in the sense of Cheng and Mordeson. We characterize fuzzy norms in terms of ascending and separating families of seminorms and prove an extension theorem for continuous linear functionals on a fuzzy normed space.
Carmen Alegre, Salvador Romaguera
doaj   +1 more source

On the extension of linear operators

International Journal of Mathematics and Mathematical Sciences, 2001
It is well known that the Hahn-Banach theorem, that is, the extension theorem for bounded linear functionals, is not true in general for bounded linear operators. A characterization of spaces for which it is true was published by Kakutani in 1940.
John J. Saccoman
doaj   +1 more source

ℂ-convexity in infinite-dimensional Banach spaces and applications to Kergin interpolation

International Journal of Mathematics and Mathematical Sciences, 2006
We investigate the concepts of linear convexity and ℂ-convexity in complex Banach spaces. The main result is that any ℂ-convex domain is necessarily linearly convex.
Lars Filipsson
doaj   +1 more source

Generalized Integral Transforms via the Series Expressions

Mathematics, 2020
From the change of variable formula on the Wiener space, we calculate various integral transforms for functionals on the Wiener space. However, not all functionals can be obtained by using this formula.
Hyun Soo Chung
doaj   +1 more source

On Four Classical Measure Theorems

Mathematics, 2021
A subset B of an algebra A of subsets of a set Ω has property (N) if each B-pointwise bounded sequence of the Banach space ba(A) is bounded in ba(A), where ba(A) is the Banach space of real or complex bounded finitely additive measures defined on A ...
Salvador López-Alfonso, Manuel López-Pellicer, Santiago Moll-López   +2 more
doaj   +1 more source

The Hahn--Banach theorem for $A$-linear operators

TURKISH JOURNAL OF MATHEMATICS, 2017
Summary: In this short paper we present a generalization of the Hahn-Banach extension theorem for \(A\)-linear operators. Some theoretical applications and results are given.
Bilici, Fatma, TURAN, BAHRİ
openaire   +2 more sources