## Applications of fixed point theorems to the Hyers-Ulam stability of functional equations – a survey.(English)Zbl 1252.39032

Summary: The fixed-point method, which is the second most popular technique of proving the Hyers-Ulam stability of functional equations, was used for the first time in 1991 by J. A. Baker in [Proc. Am. Math. Soc. 112, No. 3, 729–732 (1991; Zbl 0735.39004)], who applied a variant of Banach’s fixed-point theorem to obtain the stability of a functional equation in a single variable. However, most authors follow V. Radu’s [Fixed Point Theory 4, No. 1, 91–96 (2003; Zbl 1051.39031)] approach and make use of a theorem of J. B. Diaz and B. Margolis [Bull. Am. Math. Soc. 74, 305–309 (1968; Zbl 0157.29904)]. The main aim of this survey is to present applications of different fixed-point theorems to the theory of the Hyers-Ulam stability of functional equations.

### MSC:

 39B82 Stability, separation, extension, and related topics for functional equations 46S10 Functional analysis over fields other than $$\mathbb{R}$$ or $$\mathbb{C}$$ or the quaternions; non-Archimedean functional analysis 47H10 Fixed-point theorems

### Citations:

Zbl 0735.39004; Zbl 1051.39031; Zbl 0157.29904
Full Text: