Subadditive Mittelwerte

Ohne Zusammenfassung     

Induced bilinear maps and matrix equations

A bilinear map on vectors induces several bilinear maps on linear maps. The extent to which certain uniqueness properties of the original map carry over to the induced maps is studied. Several results on matrix equations are obtained by specialization to matrix settings.     

Subadditive Separating Maps

Let X and Y denote compact Hausdorff spaces and let K = R (real numbers) or C(complex numbers). C(X) and C(Y) denote the spaces of K-valued continuous functions on X and Y, respectively. A map H : C(X) C(Y) is separating if fg = 0 implies that HfHg = 0. Results about automatic continuity and the form of additive and linear separating maps have been developed in [1], [2], [3], [4], [5], [7], [8], and [10]. In this article similar results are developed for subadditive separating maps. We show (Theorem 5.11) that certain biseparating, subadditive bijections H are automatically continuous.     

Convolution equations and nonlinear functional equations

The survey is devoted to applications of nonlinear integral equations to linear convolution equations, their discrete analogues, and also the connection of these equations with problems of radiative transfer, in particular, with the Ambartsumyan equations.Translated from Itogi Nauki i Tekhniki, Seriya Matematicheskii Analiz, Vol. 22, pp. 175–244, 1984.     

Dichotomic maps for delayed equations

The aim of this work is to apply the method of “dichotomic maps” to study stability of the null solutions of delayed functional differential equations. Preliminaries are presented followed by proofs of main theorems on simple and asymptotic stability. Some particular cases which have been studied by others authors with more restrictive hypotheses and more elaborated methods are showed as illustrative examples enhancing the advantages of the dichotomic maps approach.     

Measure functional differential equations and functional dynamic equations on time scales

We study measure functional differential equations and clarify their relation to generalized ordinary differential equations. We show that functional dynamic equations on time scales represent a special case of measure functional differential equations. For both types of equations, we obtain results on the existence and uniqueness of solutions, continuous dependence, and periodic averaging.     

DICHROMATIC SUM EQUATIONS FOR OUTERPLANAR MAPS

This paper provides a functional equation satisfied by the dichromatic sum funetion of rooted outerplanar maps.By the equation,the dichromatic sum funetion can be found explicitiy.     

Quartic functional equations

In this paper, we solve a new functional equation

f(2x+y)+f(2x−y)=4f(x+y)+4f(x−y)+24f(x)−6f(y)     

Subadditive functions and their (pseudo-)inverses

The paper considers non-negative increasing functions on intervals with left endpoint closed at zero and investigates the duality between subadditivity and superadditivity via the inverse function and pseudo-inverses.     

Embedding problem and functional equations

In this paper we give a method for solving the functional equations arising from the differential embedding problem. We also obtain the conditions for embedding one-dimensional diffeomorphisms into differential flows.     

Orthogonality and quintic functional equations

Using the fixed point method, we prove the Hyers Ulam stability of an orthogonally quintic functional equation in Banach spaces and in non-Archimedean Banach spaces.