A note on the Hyers-Ulam stability constants of closed linear operators

Hyers-ulam Stability of the Linear Recurrence with Constant Coefficients

Problem 1.1. Given a metric group (G,·,d), a positive number ε, and a mapping f : G→ G which satisfies the inequality d( f (xy), f (x) f (y)) ≤ ε for all x, y ∈ G, do there exist an automorphism a of G and a constant δ depending only on G such that d(a(x), f (x)) ≤ δ for all x ∈G? If the answer to this question is affirmative, we say that the equation a(xy) = a(x)a(y) is stable. A first answer ...

Hyers-Ulam Stability of Weighted Composition Operators on L^p-Spaces

Hyers-ulam Stability of Isometries

Let X and Y be real Banach spaces. A mapping q5 : X --t Y is called an &-isometry if 1 IIq5(z) ~$(y)jl 11% yI/ I 5 E holds for all z,y E X. If q5 is surjective, then its distance to the set of all isometries of X onto Y is at most yx~, where yx denotes the Jung constant of X.

Hyers–ulam Stability of a Polynomial Equation

The aim of this paper is to prove the stability in the sense of Hyers–Ulam stability of a polynomial equation. More precisely, if x is an approximate solution of the equation x + αx + β = 0, then there exists an exact solution of the equation near to x.

Hyers-ulam stability of exact second-order linear differential equations

* Correspondence: baak@hanyang. ac.kr Department of Mathematics, Research Institute for Natural Sciences, Hanyang University, Seoul 133-791, South Korea Full list of author information is available at the end of the article Abstract In this article, we prove the Hyers-Ulam stability of exact second-order linear differential equations. As a consequence, we show the Hyers-Ulam stability of the fo...