In the present paper we characterize, in terms of characters, additive functions and matrix
elements of irreducible two-dimensional representations, the continuous solutions of some …

In this paper, we will prove the superstability of the functional equation∑ ϕ∈ Φ∫ K f (xk ϕ
(y) k-1) dw K (k)=| Φ| f (x) g (y), x, y∈ G, which is bounded by the real functions φ (x), ψ (y) or …

The aim of this paper is to study the superstability for the mixed trigonometric functional
equation:,,),()(2))(()(Gyxygxfyxfxyf∈=− σ)(, gfEand the stability of the Pexider type functional …

We generalize the super-stability result for cosine functional equation mappings with values
in the field of complex numbers to the case of an arbitrary Hilbert space with the Hadamard …

In the present paper we characterize, in terms of characters, multiplicative functions, the
continuous solutions of some functional equations for mappings defined on a monoid and …

Let $ X $ be a vector space over a field $ K $ of real or complex numbers. We will prove the
superstability of the following Go {\l}\c {a} b-Schinzel type equation $$ f (x+ g (x) y)= f (x) f (y) …

AROUND THE GER-ŠEMRL SUPERSTABILITY THEOREM 1. Introduction In 1940, SM Ulam,
presenting a list of unsolved problems, asked t Page 1 Bulletin of Mathematical Analysis and …