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In this paper, we investigate homomorphisms between $C^*$-ternary algebras and derivations on $C^*$-ternary algebras, associated with the following functional equation…

Operator Algebras · Mathematics 2008-12-17 M. Bavand Savadkouhi , M. Eshaghi Gordji , N. Ghobadipour

By adopting the direct method and fixed point method, we prove that the Hyers-Ulam stability of the following additive-quadratic functional equation \begin{equation} f(x+y, z+w)+f(x-y, z-w)-2 f(x, z)-2 f(x, w)=0 \end{equation} in…

Functional Analysis · Mathematics 2022-03-08 Linlin Fu , Qi Liu , Yongjin Li

In this work, we prove the generalised Hyer Ulam stability of the following functional equation \begin{equation}\label{Eq-1} \phi(x)+\phi(y)+\phi(z)=q \phi\left(\sqrt[s]{\frac{x^s+y^s+z^s}{q}}\right),\qquad |q| \leq 1 \end{equation} and $s$…

Functional Analysis · Mathematics 2024-08-21 Abderrahman Baza , Mohamed Rossafi

In this paper, we study the Hyers-Ulam stability of the following equation \begin{multline*} \phi(x+y-z)+\phi(x+z-y)+\phi(y+z-x)=\phi (x-y)+\phi(x-z)+\phi(z-y) +\phi(x)+\phi(y) +\phi(z) \end{multline*} in modular space, with or without…

Functional Analysis · Mathematics 2025-05-14 Abderrahman Baza , Mohamed Rossafi , Arul Joseph Gnanaprakasam

Using the fixed point theorem we establish the Hyers-Ulam-Rassias stability of the generalized Pexider functional equation $$\frac{1}{\mid K\mid}\sum_{k\in K}f(x+k\cdot y)=g(x)+h(y),\;\;x,y\in E$$ from a normed space $E$ into a complete…

Functional Analysis · Mathematics 2014-06-17 E. Elqorachi , John M. Rassias , B. Bouikhalene

In this paper, we establish the conditional Hyers-Ulam-Rassias stability of the generalized Jensen functional equation $r f \left (\frac{sx+ty}{r}) = s g(x) + t h(y)$ on various restricted domains such as inside balls, outside balls, and…

Functional Analysis · Mathematics 2021-07-23 Soon-Mo Jung , Mohammad Sal Moslehian , Prasanna K. Sahoo

In this paper, we obtain the general solution and the stability result for the following functional equation in random normed spaces (in the sense of Sherstnev) under arbitrary $t$-norms…

Functional Analysis · Mathematics 2009-03-09 M. Eshaghi Gordji , M. Bavand Savadkouhi , C. Park

The paper deals with the stability of the fundamental equation of information of multiplicative type. It will be proved that the equation in question is stable in the sense of Hyers and Ulam under some assumptions. This result will be…

Classical Analysis and ODEs · Mathematics 2013-07-03 Eszter Gselmann

In this paper, we establish the generalized Hyers--Ulam--Rassias stability of homomorphisms between ternary algebras associted to the generalized Jensen functional equation $r f(\frac{sx+ty}{r}) = s f(x) + t f(y)$.

Functional Analysis · Mathematics 2021-07-23 Mohammad Sal Moslehian , Laszlo Szekelyhidi

In this paper, using the fixed point and direct methods, we prove the generalized Hyers-Ulam-Rassias stability of a Cauchy-Jensen additive functional equation in various normed spaces. The concept of Hyers-Ulam-Rassias stability originated…

Functional Analysis · Mathematics 2020-02-24 H. Azadi Kenary , Th. M. Rassias

This paper explores the Hyers-Ulam stability of generalized Jensen additive and quadratic functional equations in \(\beta\)-homogeneous \(F\)-space, showing that approximately satisfying mappings have a unique exact approximating…

Functional Analysis · Mathematics 2025-08-15 Jing Zhang , Qi Liu , Yongmo Hu , Linlin Fu , Yuxin Wang , Jinyu Xia , John Michael Rassias , Choonkil Park , Yongjin Li

In this paper we will investigate the solutions and stability of the generalized variant of Wilson's functional equation $$ (E):\;\;\;\; f(xy)+\chi(y)f(\sigma(y)x)=2f(x)g(y),\; x,y\in G,$$ where $G$ is a group, $\sigma$ is an involutive…

Classical Analysis and ODEs · Mathematics 2015-05-26 Elqorachi Elhoucien , Redouani Ahmed

Using the fixed point alternative theorem we establish the orthogonal stability of quadratic functional equation of Pexider type $f(x+y)+g(x-y)=h(x)+k(y)$, where $f, g, h, k$ are mappings from a symmetric orthogonality space to a Banach…

Functional Analysis · Mathematics 2021-07-23 M. Mirzavaziri , M. S. Moslehian

We consider Hyers-Ulam stability of a functional equation for continuous functions on a space on which a topological group acts, analogous to the additive functional equation on a group. We show, among other things, that our generalized…

Functional Analysis · Mathematics 2015-10-08 Maysam Maysami Sadr

In this paper, we establish the generalized Hyers--Ulam--Rassias stability of $C^*$-ternary ring homomorphisms associated to the Trif functional equation \begin{eqnarray*} d \cdot C_{d-2}^{l-2} f(\frac{x_1+... +x_d}{d})+…

Functional Analysis · Mathematics 2008-04-30 Mohammad Sal Moslehian

Using the direct method, we prove the generalised Hyers-Ulam stability of the following functional equation \begin{equation} \phi(x+y, z+w)+\phi(x-y, z-w)-2 \phi(x, z)-2 \phi(x, w)=0 \end{equation} in modular space satisfying the Fatou…

General Mathematics · Mathematics 2024-06-25 Abderrahman Baza , Mohamed Rossafi , Choonkil Park

In this paper, we examine the Hyers-Ulam and Hyers-Ulam-Rassias stability of solutions of a general class of nonlinear Volterra integral equations. By using a fixed point alternative and improving a technique commonly used in similar…

Classical Analysis and ODEs · Mathematics 2021-05-26 Süleyman Öğrekçi , Yasemin Başcı , Adil Mısır

The foundation of locally convex cone theory relies on order-theoretic concepts that induce specific topological frameworks. Within this structure, cones naturally possess three distinct topologies: lower, upper, and symmetric. In this…

Functional Analysis · Mathematics 2025-04-11 Jafar Mohammadpour , Abbas Najati , Iz-iddine EL-Fassi

In this paper, we investigate some hyperstability results, inspired by the concept of Ulam stability, for the following functional equations: \begin{equation} \varphi(x+y)+\varphi(x-y)=2\varphi(x)+2\varphi(y) \end{equation} \begin{equation}…

Functional Analysis · Mathematics 2024-10-15 Abderrahman Baza , Mohamed Rossafi , Mohammed Mouniane

In this paper we obtain a result on Hyers-Ulam stability of the linear functional equation in a single variable $f(\varphi(x)) = g(x) \cdot f(x)$ on a complete metric group.

Functional Analysis · Mathematics 2015-12-16 Soon-Mo Jung , Dorian Popa , Michael Th. Rassias