The notion of stability of functional equations of several variables in the sense used here
had its origins more than half a century ago when S. Ulam posed the fundamental problem …

On the Stability of Functional Equations in Banach Spaces Page 1 Ž . Journal of Mathematical
Analysis and Applications 251, 264284 2000 doi:10.1006rjmaa.2000.7046, available online …

The paper is a survey about Hyers—Ulam stability of functional equations and systems in
several variables. Its content is divided in the following chapters: 1.—Introduction. Historical …

On a Problem of G. Isac and Th. M. Rassias Concerning the Stability of Map**s Page 1 Ž .
Journal of Mathematical Analysis and Applications 261, 543553 2001 doi:10.1006rjmaa.2001.7539 …

A new stability concept is introduced which generalizes the notion of the Hyers–Ulam
stability. The Cauchy functional equation is shown to be stable in this more general sense …

The main result of this paper offers a necessary and sufficient condition for the existence of
an additive selection of a weakly compact convex set-valued map defined on an amenable …

Let f: S→ X map an abelian semigroup (S,+) into a Banach space (X‖⋅‖). We deal with
stability of the following alternative functional equation We assume that for all x, y∈ S, where …

Let G be an amenable metric semigroup with nonempty center, let E be a reflexive Banach
space, and let ƒ: G→ E be a given function. By Cƒ: G× G→ E we understand the Cauchy …

We study the stability of the Drygas functional equation: mixing the direct method of the proof
with the method of the invariant means. Drop** the assumption about the domain to be an …

The present paper is devoted to the memory of DH Hyers, who contributed to the theory of
stability of functional equations and inequalities with fundamental ideas and results. Here …