Results 41 to 50 of about 505 (94)

Fuzzy stability of multi-additive mappings

Demonstratio Mathematica
The main aim of this study is to establish some stability results concerning the multi-additive mappings by applying the so-called direct (Hyers) method and the alternative fixed approach in the setting of fuzzy normed spaces.
Park Choonkil, Bodaghi Abasalt, Donganont Mana   +2 more
doaj   +1 more source

Characterization of Classes of Polynomial Functions

, 2014
In this paper some classes of local polynomial functions on abelian groups are characterized by the properties of their variety. For this characterization we introduce a numerical quantity depending on the variety of the local polynomial only.
Almira, J. M., Székelyhidi, L.
core   +1 more source

Orthogonal Stability of an Additive-Quadratic Functional Equation

Fixed Point Theory and Applications, 2011
Using the fixed point method and using the direct method, we prove the Hyers-Ulam stability of an orthogonally additive-quadratic functional equation in orthogonality spaces. (2010) Mathematics Subject Classification: Primary 39B55; 47H10; 39B52; 46H25.
Park Choonkil
doaj  

On the stability of J$^*-$derivations

, 2009
In this paper, we establish the stability and superstability of $J^*-$derivations in $J^*-$algebras for the generalized Jensen--type functional equation $$rf(\frac{x+y}{r})+rf(\frac{x-y}{r})= 2f(x).$$ Finally, we investigate the stability of $J ...
A. Ebadian, Czerwik, Cădariu, Cădariu, Cădariu, Cădariu, Elin, Harris, Harris, Hyers, Hyers, Hyers, Jung, M. Eshaghi Gordji, M.B. Ghaemi, Moslehian, Park, Park, Park, Park, Radu, Rassias, Rassias, S. Kaboli Gharetapeh, S. Shams, Ulam   +25 more
core   +2 more sources

Approximate *-derivations and approximate quadratic *-derivations on C*-algebras

Journal of Inequalities and Applications, 2011
In this paper, we prove the stability of *-derivations and of quadratic *-derivations on Banach *-algebras. We moreover prove the superstability of *-derivations and of quadratic *-derivations on C*-algebras.
Park Choonkil, Jang Sun
doaj  

Superstability of generalized cauchy functional equations

Advances in Difference Equations, 2011
In this paper, we consider the stability of generalized Cauchy functional equations such as Especially interesting is that such equations have the Hyers-Ulam stability or superstability whether g is identically one or not.
Chung Soon-Yeong, Lee Young-Su
doaj  

Superstability of functional equations related to spherical functions

Open Mathematics, 2017
In this paper we prove stability-type theorems for functional equations related to spherical functions. Our proofs are based on superstability-type methods and on the method of invariant means.
Székelyhidi László
doaj   +1 more source

On the stability of pexider functional equation in non-archimedean spaces

Journal of Inequalities and Applications, 2011
In this paper, the Hyers-Ulam stability of the Pexider functional equation in a non-Archimedean space is investigated, where σ is an involution in the domain of the given mapping f.
Vaezpour Seiyed, Saadati Reza, Sadeghi Zahra   +2 more
doaj  

Generalized Polynomials on Semigroups

Annales Mathematicae Silesianae
This article has two main parts. In the first part we show that some of the basic theory of generalized polynomials on commutative semi-groups can be extended to all semigroups.
Ebanks Bruce
doaj   +1 more source

On the Alienation of Multiplicative and Additive Functions

Annales Mathematicae Silesianae
Given S a semigroup. We study two Pexider-type functional equations fxy+gxy=fx+fy+gxgy,    x, y∈S,f\left( {xy} \right) + g\left( {xy} \right) = f\left( x \right) + f\left( y \right) + g\left( x \right)g\left( y \right), \;\;\;\;x,\;y \in S, and ...
Chakiri Mohamed, Chahbi Abdellatif, Elqorachi Elhoucien   +2 more
doaj   +1 more source