On the Superstability of Lobačevskiǐ’s Functional Equations with Involution

Let G be a uniquely 2-divisible commutative group and let f,g:G→C and σ:G→G be an involution. In this paper, generalizing the superstability of Lobačevskiǐ’s functional equation, we consider f(x+σy)/22-g(x)f(y)≤ψ(x) or ψ(y) for all x,y∈G, where ψ:G→R+. As a direct consequence, we find a weaker condi...

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Bibliographic Details
Main Authors: Jaeyoung Chung, Bogeun Lee, Misuk Ha
Format: Article
Language:English
Published: Hindawi Limited 2016-01-01
Series:Journal of Function Spaces
Online Access:http://dx.doi.org/10.1155/2016/1036094
Description
Summary:Let G be a uniquely 2-divisible commutative group and let f,g:G→C and σ:G→G be an involution. In this paper, generalizing the superstability of Lobačevskiǐ’s functional equation, we consider f(x+σy)/22-g(x)f(y)≤ψ(x) or ψ(y) for all x,y∈G, where ψ:G→R+. As a direct consequence, we find a weaker condition for the functions f satisfying the Lobačevskiǐ functional inequality to be unbounded, which refines the result of Găvrută and shows the behaviors of bounded functions satisfying the inequality. We also give various examples with explicit involutions on Euclidean space.
ISSN:2314-8896
2314-8888