Results 21 to 30 of about 84 (83)

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

Hyers–Ulam Stability of Mixed Quintic and Sextic Equations in Matrix‐Valued Non‐Archimedean Random Normed Spaces via Fixed Point Methods

Journal of Mathematics, Volume 2026, Issue 1, 2026.
This paper establishes the Hyers–Ulam stability of mixed quintic and sextic functional equations within matrix non‐Archimedean random normed spaces. Using fixed‐point techniques, we derive conditions under which approximate solutions guarantee exact solutions, generalizing stability results to these structured probabilistic spaces.
Khalil Shahbazpour, Ali Ebadian, Ali Jabbari, A. M. Nagy   +3 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

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

Estimation of Inexact Multimixed Additive‐Quadratic Mappings in Fuzzy Normed Spaces

Journal of Mathematics, Volume 2025, Issue 1, 2025.
In the current study, we introduce a new model of multimixed additive‐quadratic mapping and then show that the system of several mixed additive‐quadratic equations defining a multimixed additive‐quadratic mapping can be unified and presented as a single equation. We also show that such mappings under some conditions are multi‐additive, multi‐quadratic,
Abasalt Bodaghi, Pramita Mishra
wiley   +1 more source

Fixed Point Technique: Stability Analysis of Quadratic Functional Equation in Various Quasi‐Banach Spaces

Journal of Mathematics, Volume 2025, Issue 1, 2025.
In this present work, we derive the solution of a quadratic functional equation and investigate the Ulam stability of this equation in Banach spaces using fixed point and direct techniques. Mainly, we examine the stability results in quasi‐β‐Banach spaces and quasi‐fuzzy β‐Banach spaces by means of direct method as well as quasi‐Banach spaces by means ...
Kandhasamy Tamilvanan, Faruk Özger, S. A. Mohiuddine, Naeem Ahmad, Masho Jima Kabeto, Valerii Obukhovskii   +5 more
wiley   +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

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  

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

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
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