Stability of functional equations in dislocated quasi-metric spaces
Journal Title: Annales Mathematicae Silesianae - Year 2018, Vol 32, Issue
Abstract
We present a result on the generalized Hyers–Ulam stability of a functional equation in a single variable for functions that have values in a complete dislocated quasi-metric space. Next, we show how to apply it to prove stability of the Cauchy functional equation and the linear functional equation in two variables, also for functions taking values in a complete dislocated quasi-metric space. In this way we generalize some earlier results proved for classical complete metric spaces.
Authors and Affiliations
Beata Hejmej
Stability of functional equations in dislocated quasi-metric spaces
We present a result on the generalized Hyers–Ulam stability of a functional equation in a single variable for functions that have values in a complete dislocated quasi-metric space. Next, we show how to apply it to prove...
An infinite natural product
We study a countably infinite iteration of the natural product between ordinals. We present an “effective” way to compute this countable natural product; in the non trivial cases the result depends only on the natural su...
The behaviour of weak solutions of boundary value problems for linear elliptic second order equations in unbounded cone-like domains
We investigate the behaviour of weak solutions of boundary value problems (Dirichlet, Neumann, Robin and mixed) for linear elliptic divergence second order equations in domains extending to infinity along a cone. We find...
Invariant means on Banach spaces
In this paper we study some generalization of invariant means on Banach spaces. We give some sufficient condition for the existence of the invariant mean and some examples where we have not it.
On a functional equation related to two-sided centralizers
The main aim of this manuscript is to prove the following result. Let $n >2$ be a fixed integer and $R$ be a $k$-torsion free semiprime ring with identity, where $k∈{2,n−1,n}$. Let us assume that for the additive mapping...