Academic Journal

On quadratic set valued functions

Bibliographic Details
Title: On quadratic set valued functions
Authors: Nikodem, Kazimierz
Source: Publicationes Mathematicae Debrecen. 30:297-301
Publisher Information: University of Debrecen/ Debreceni Egyetem, 2022.
Publication Year: 2022
Subject Terms: Functional equations for functions with more general domains and/or ranges, quadratic functionals, 0101 mathematics, set valued functions, 01 natural sciences, Functional equations and inequalities
Description: A set valued function \(U:{\mathbb{R}}\to 2^ X\) (where X is a real normed space) is said to be quadratic iff \(U(s+t)+U(s-t)=2U(s)+2U(t),\) for all s,\(t\in {\mathbb{R}}\). There is proved, among others, that if a quadratic set valued function U:\({\mathbb{R}}\to CC(X)\) (where CC(X) denotes the family of all compact, convex and non-empty subsets of X) is bounded on a subset of \({\mathbb{R}}\) of positive inner Lebesgue measure or if it is measurable, then it is of the form \(U(t)=t^ 2U(1),\) \(t\in {\mathbb{R}}\).
Document Type: Article
File Description: application/xml
ISSN: 0033-3883
DOI: 10.5486/pmd.1983.30.3-4.11
Access URL: https://zbmath.org/3853649
Accession Number: edsair.doi.dedup.....94e87604c843355cbb5f968cb8fdda6f
Database: OpenAIRE
Be the first to leave a comment!
You must be logged in first