Results 21 to 30 of about 60 (59)

Hyers-Ulam stability of isometries on bounded domains-II

Demonstratio Mathematica, 2023
The question of whether there is a true isometry approximating the ε\varepsilon -isometry defined in the bounded subset of the nn-dimensional Euclidean space has long been considered an interesting question.
Choi Ginkyu, Jung Soon-Mo
doaj   +1 more source

Stability Results for Some Functional Equations on 2‐Banach Spaces With Restricted Domains

Journal of Mathematics, Volume 2025, Issue 1, 2025.
We have a normed abelian group G,.∗,+ and a 2‐pre‐Hilbert space Y with linearly independent elements u and v. Our goal is to prove that any odd map f:G⟶Y satisfying the inequality ‖f(x) + f(y), z‖ ⩽ ‖f(x + y), z‖, z ∈ {u, v}, for all x,y∈G with ‖x‖∗ + ‖y‖∗ ≥ d and some d ≥ 0, is additive. Then, we examined the stability issue correlated with Cauchy and
M. R. Abdollahpour, A. Najati, Y. Khedmati Yengejeh, Ali Jaballah   +3 more
wiley   +1 more source

On a functional equation that has the quadratic-multiplicative property

Open Mathematics, 2020
In this article, we obtain the general solution and prove the Hyers-Ulam stability of the following quadratic-multiplicative functional equation:ϕ(st−uv)+ϕ(sv+tu)=[ϕ(s)+ϕ(u)][ϕ(t)+ϕ(v)]\phi (st-uv)+\phi (sv+tu)={[}\phi (s)+\phi (u)]{[}\phi (t)+\phi (v ...
Park Choonkil, Tamilvanan Kandhasamy, Balasubramanian Ganapathy, Noori Batool, Najati Abbas   +4 more
doaj   +1 more source

Thermal Applications of Stability Analysis of Cubic Functional Equation in Banach Spaces and Intuitionistic Fuzzy Normed Spaces

Journal of Mathematics, Volume 2025, Issue 1, 2025.
This paper analyzes the stability of the Euler–Lagrange–Jensen cubic functional equation in the context of Banach spaces and Intuitionistic Fuzzy Normed Spaces (IFN‐Spaces). We use both direct and fixed point techniques to establish the generalized Ulam stability of the cubic functional equation under various norm‐based constraints.
Subramani Karthikeyan, Kandhasamy Tamilvanan, John Michael Rassias, Masho Jima Kabeto, Nan-Jing Huang   +4 more
wiley   +1 more source

On Almost Everywhere K-Additive Set-Valued Maps

Annales Mathematicae Silesianae
Let X be an Abelian group, Y be a commutative monoid, K ⊂Y be a submonoid and F : X → 2Y \ {∅} be a set-valued map. Under some additional assumptions on ideals ℐ1 in X and ℐ2 in X2, we prove that if F is ℐ2-almost everywhere K-additive, then there ...
Jabłońska Eliza
doaj   +1 more source

Fuzzy Stability of Generalized Mixed Type Cubic, Quadratic, and Additive Functional Equation

Journal of Inequalities and Applications, 2011
In this paper, we prove the generalized Hyers-Ulam stability of generalized mixed type cubic, quadratic, and additive functional equation, in fuzzy Banach spaces. 2010 Mathematics Subject Classification: 39B82; 39B52.
Shin Dong, Park Choonkil, Gordji Madjid, Kamyar Mahdie, Khodaei Hamid   +4 more
doaj  

Approximately cubic functional equations and cubic multipliers

Journal of Inequalities and Applications, 2011
In this paper, we prove the Hyers-Ulam stability and the superstability for cubic functional equation by using the fixed point alternative theorem. As a consequence, we show that the cubic multipliers are superstable under some conditions.
Alias Idham, Bodaghi Abasalt, Ghahramani Mohammad   +2 more
doaj  

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

Fuzzy stabilities of a new hexic functional equation in various spaces

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2022
The advantage of various fuzzy normed spaces is to analyse impreciseness and ambiguity that arise in modelling problems. In this paper, various classical stabilities of a new hexic functional equation in di erent fuzzy spaces like fuzzy Banach space ...
Dutta Hemen, Kumar B.V. Senthil, Sabarinathan S.   +2 more
doaj   +1 more source

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