On a System of Functional Equations
On a System of Functional Equations in Information Theory.
On an open problem regarding an integral inequality.
On approximate solutions of a system of functional equations
On continuous solutions of systems of functional equations
On convex and *-concave multifunctions
A continuous multifunction F:[a,b] → clb(Y) is *-concave if and only if the inclusion holds for every s,t ∈ [a,b], s < t.
On derivations on certain function spaces and their relation to the differential operator. (Über Derivationen auf gewissen Funktionenräumen und deren Beziehung zum Differentiationsoperator.)
On differentiable solutions of some systems of functional equations of p-th order
On functional inequalities originating from module Jordan left derivations.
On functions with the Cauchy difference bounded by a functional. II.
On Functions with the Cauchy Difference Bounded by a Functional
K. Baron and Z. Kominek [2] have studied the functional inequality f(x+y) - f(x) - f(y) ≥ ϕ (x,y), x, y ∈ X, under the assumptions that X is a real linear space, ϕ is homogeneous with respect to the second variable and f satisfies certain regularity conditions. In particular, they have shown that ϕ is bilinear and symmetric and f has a representation of the form f(x) = ½ ϕ(x,x) + L(x) for x ∈ X, where L is a linear function. The purpose of the present...
On generalized hyperbolic functions and their characterization by functional equations.
On generalized invariant means and separation theorems.
On Hadamard integral inequalities involving two log-preinvex functions.
On measurable solutions of a functional equation and its application to information theory
On subaddidive and Ψ-additive mappings
On subadditive functions and ψ-additive mappings
In [4], assuming among others subadditivity and submultiplicavity of a function ψ: [0, ∞)→[0, ∞), the authors proved a Hyers-Ulam type stability theorem for “ψ-additive” mappings of a normed space into a normed space. In this note we show that the assumed conditions of the function ψ imply that ψ=0 and, consequently, every “ψ-additive” mapping must be additive
On the Cauchy functional inequality in Banach modules.
On the characterization of quasiarithmetic means with weight function.
On the continuity of Q-convex functions and additive functions.