Equations fonctionnelles et recherche de sous-groupes.
Équations fonctionnelles liées aux groupes linéaires commutatifs
Equations of the form H(x...y) = ...fi(x)gi(y).
Equivalence of 'Cube' and 'Octahedron' Functional Equations.
Erdős problem and quadratic equation.
Errata for the paper: ``Almost approximately convex functions'
Errata to my paper "On some functional equations and their applications".
Espacios de producto interno (II).
Among normal linear spaces, the inner product spaces (i.p.s.) are particularly interesting. Many characterizations of i.p.s. among linear spaces are known using various functional equations. Three functional equations characterizations of i.p.s. are based on the Frchet condition, the Jordan and von Neumann identity and the Ptolemaic inequality respectively. The object of this paper is to solve generalizations of these functional equations.
Etude des Solutions d΄ une Classe d΄ Equatiens Integrodifferentielles Non lineaires aux Operateurs Hyperboliques Ayant Pour Limites des Fonctionnelles Integrales
Étude sur les équations fonctionnelles
Euler-Lagrange type cubic operators and their norms on space.
Exact asymptotics of nonlinear difference equations with levels and
We study a class of nonlinear difference equations admitting a -Gevrey formal power series solution which, in general, is not - (or Borel-) summable. Using right inverses of an associated difference operator on Banach spaces of so-called quasi-functions, we prove that this formal solution can be lifted to an analytic solution in a suitable domain of the complex plane and show that this analytic solution is an accelero-sum of the formal power series.
Existence and uniqueness of solutions of non-linear functional equations of r-th order
Existence and uniqueness of the analytic solution of a nonlinear functional equation. (Russisch).
Existence criteria for positive solutions of a nonlinear difference inequality
This paper is concerned with a class of nonlinear difference inequalities which include many different classes of difference inequalities and equations as special cases. By means of a Riccati type transformation, necessary and sufficient conditions for the existence of eventually positive solutions and positive nonincreasing solutions are obtained. Various type of comparison theorems are also derived as applications, which extends many theorems in the literature.
Existence of differentiable solutions of a system of functional equations of first order
Existence of entire solutions of nonlinear difference equations
In this paper we obtain that there are no transcendental entire solutions with finite order of some nonlinear difference equations of different forms.
Existence of solutions for equations involving iterated functional series.
Existence of solutions of impulsive boundary value problems for singular fractional differential systems
A class of impulsive boundary value problems of fractional differential systems is studied. Banach spaces are constructed and nonlinear operators defined on these Banach spaces. Sufficient conditions are given for the existence of solutions of this class of impulsive boundary value problems for singular fractional differential systems in which odd homeomorphism operators (Definition 2.6) are involved. Main results are Theorem 4.1 and Corollary 4.2. The analysis relies on a well known fixed point...
Exponential estimates of solutions of difference equations with continuous time.