Stability of general Newton functional equations for logarithmic spirals.
Stability of generalized quadratic functional equation on a set of measure zero
In this paper we prove the Hyers-Ulam stability of the following K-quadratic functional equation [...] where E is a real (or complex) vector space. This result was used to demonstrate the Hyers-Ulam stability on a set of Lebesgue measure zero for the same functional equation.
Stability of homomorphisms and generalized derivations on Banach algebras.
Stability of mixed type cubic and quartic functional equations in random normed spaces.
Stability of multipliers on Banach algebras.
Stability of quadratic functional equations via the fixed point and direct method.
Stability of quartic functional equations in the spaces of generalized functions.
Stability of the Cauchy equation in ordered fields.
Stability of the Cauchy functional equation in quasi-Banach spaces
Let X be a quasi-Banach space. We prove that there exists K > 0 such that for every function w:ℝ → X satisfying ||w(s+t)-w(s)-w(t)|| ≤ ε(|s|+|t|) for s,t ∈ ℝ, there exists a unique additive function a:ℝ → X such that a(1)=0 and ||w(s)-a(s)-sθ(log₂|s|)|| ≤ Kε|s| for s ∈ ℝ, where θ: ℝ → X is defined by for k ∈ ℤ and extended in a piecewise linear way over the rest of ℝ.
Stability of the Cauchy-Jensen functional equation in -algebras: a fixed point approach.
Stability of the Jensen-type functional equation in -algebras: a fixed point approach.
Stability of the Lobacevski equation.
Stability problem of Ulam for Euler-Lagrange quadratic mappings.
Stability problems of quintic mappings in quasi--normed spaces.
Stability results for some functional equations of quadratic-type.
Standard threads and distributivity.
Strictly quadratic functional equations on quasigroups. I.
Subadditive functions on modules and subgroups of abelian groups.
Subgroups of the Clifford group.
Subgroups of the group Zn and a generalization of the Golab-Schinzel functional equation.