A functional equation characterizing cubic polynomials and its stability.
A functional equation characterizing monomial functions used in permanence theory for ecological differential equations.
A functional equation connected with the sine addition theorem
A functional equation for quadratic forms.
A functional equation involving f and .
A functional equation of Aczél and Chung in generalized functions.
A functional equation of Ih-Ching Hsu.
A functional equation originating from elliptic curves.
A functional equation related to an equality of means problem
The functional equation (F(x)-F(y))/(x-y) = (G(x)+G(y))(H(x)+H(y)) where F,G,H are unknown functions is considered. Some motivations, coming from the equality problem for means, are presented.
A Functional Equation with Differences
A functional inequality characterizing convex functions, conjugacy and a generalization of Hölder's and Minkowski's inequalities.
A Functional Inequality for Entire Functions Generalizing the Sine Functional Equation. (Short Communication).
A functional inequality for real-analytic functions.
A functional inequality in restricted domains of Banach modules.
A functional-analytic method for the study of difference equations.
A fundamental functional equation for vector lattices.
A Fundamental Functional Equation for Vector Lattices. (Short Communication).
A Galois -groupoid for -difference equations
We first recall Malgrange’s definition of -groupoid and we define a Galois -groupoid for -difference equations. Then, we compute explicitly the Galois -groupoid of a constant linear -difference system, and show that it corresponds to the -difference Galois group. Finally, we establish a conjugation between the Galois -groupoids of two equivalent constant linear -difference systems, and define a local Galois -groupoid for Fuchsian linear -difference systems by giving its realizations.
A Gauss type functional equation.
A general class of iterative equations on the unit circle
A class of functional equations with nonlinear iterates is discussed on the unit circle . By lifting maps on and maps on the torus to Euclidean spaces and extending their restrictions to a compact interval or cube, we prove existence, uniqueness and stability for their continuous solutions.