Results 31 to 40 of about 112 (106)

Extension theorems of Hahn-Banach type for nonlinear disjointly additive functionals and operators in Lebesgue spaces

open access: yesJournal of Functional Analysis, 1977
AbstractLet (Ω, τ, M) be a nonatomic separable finite measure space. Every continuous functional N on Lp(m), 1 ⩽ p < ∞, which is disjointly additive in the sense N(u + v) = N(u) + N(v) whenever uv = 0, is known to be representable by an integral with a nonlinear Caratheodory kernel.
Marcus, Moshe, Mizel, Victor J
openaire   +1 more source

On Hermite–Hadamard Inequalities for Generalized Quantum Interval Calculus

open access: yesJournal of Mathematics, Volume 2026, Issue 1, 2026.
In this paper, we develop the theory of β,gH‐calculus for interval‐valued functions by combining the β‐functions with the generalized Hukuhara difference. Within this framework, we establish various properties related to β,gH‐differentiation and β,gH‐integration.
Muhammad Umer Azam   +4 more
wiley   +1 more source

Existence, Uniqueness, Stability, and Numerical Solution of Second‐Order Quantum Difference Equations: A General Approach via the Riccati Method and Chebyshev Collocation

open access: yesJournal of Mathematics, Volume 2026, Issue 1, 2026.
In this paper, we investigate the stability and numerical solution of second‐order linear nonhomogeneous equations with the general quantum B‐difference operator. We prove Hyers–Ulam stability (HU s) and Hyers–Ulam–Rassias stability (HUR s) for these equations using a Riccati equation approach and variation of parameters technique.
Karima M. Oraby   +3 more
wiley   +1 more source

Weak solutions for a singular beam equation

open access: yesZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik, Volume 105, Issue 12, December 2025.
Abstract This paper deals with a dynamic Gao beam of infinite length subjected to a moving concentrated Dirac mass. Under appropriate regularity assumptions on the initial data, the problem possesses a weak solution which is obtained as the limit of a sequence of solutions of regularized problems.
Olena Atlasiuk   +2 more
wiley   +1 more source

Conformal optimization of eigenvalues on surfaces with symmetries

open access: yesJournal of the London Mathematical Society, Volume 112, Issue 6, December 2025.
Abstract Given a conformal action of a discrete group on a Riemann surface, we study the maximization of Laplace and Steklov eigenvalues within a conformal class, considering metrics invariant under the group action. We establish natural conditions for the existence and regularity of maximizers. Our method simplifies the previously known techniques for
Denis Vinokurov
wiley   +1 more source

The domination theorem for operator classes generated by Orlicz spaces

open access: yesMathematische Nachrichten, Volume 298, Issue 11, Page 3576-3598, November 2025.
Abstract We study lattice summing operators between Banach spaces focusing on two classes, ℓφ$\ell _\varphi$‐summing and strongly φ$\varphi$‐summing operators, which are generated by Orlicz sequence lattices ℓφ$\ell _\varphi$. For the class of strongly φ$\varphi$‐summing operators, we prove the domination theorem, which complements Pietsch's ...
D. L. Fernandez   +3 more
wiley   +1 more source

Existence of Weak Solutions for a Degenerate Goursat‐Type Linear Problem

open access: yesMathematical Methods in the Applied Sciences, Volume 48, Issue 15, Page 14334-14341, October 2025.
ABSTRACT For a generalization of the Gellerstedt operator with mixed‐type Dirichlet boundary conditions to a suitable Tricomi domain, we prove the existence and uniqueness of weak solutions of the linear problem and for a generalization of this problem.
Olimpio Hiroshi Miyagaki   +2 more
wiley   +1 more source

A geometric form of the Hahn-Banach extension theorem for L0 linear functions and the Goldstine-Weston theorem in random normed modules

open access: yes, 2011
In this paper, we present a geometric form of the Hahn-Banach extension theorem for $L^{0}-$linear functions and prove that the geometric form is equivalent to the analytic form of the Hahn-Banach extension theorem. Further, we use the geometric form to give a new proof of a known basic strict separation theorem in random locally convex modules ...
Zhao, Shien, Shi, Guang
openaire   +2 more sources

From linear to metric functional analysis. [PDF]

open access: yesProc Natl Acad Sci U S A, 2021
Karlsson A.
europepmc   +1 more source

Lipschitz Carnot-Carathéodory Structures and their Limits. [PDF]

open access: yesJ Dyn Control Syst, 2023
Antonelli G   +2 more
europepmc   +1 more source

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