Abstract
Let \( X \) be a normed space over \( \mathbb{F} \in\{ \mathbb{R}, \mathbb{C}\} \), \( Y \) be a non-Archimedean Banach space over a non-Archimedean non-trivial field \(\mathbb{K}\) and \(c,d,C,D\) be constants such that, \( c, d \in \mathbb{F}\setminus\{0\} \) and \( C, D \in \mathbb{K}\setminus\{0\} \). In this paper, some preliminaries on non-Archimedean Banach spaces and the concept of hyperstability are presented. Next, the well-known fixed point method [7, Theorem1] is reformulated in non-Archimedean Banach spaces. Using this method, we prove that the general linear functional equation \( h(cx+dy)= Ch(x)+Dh(y) \) is hyperstable in the class of functions \( h:X\rightarrow Y \). In fact, by exerting some natural assumptions on control function \( \gamma:X^{2}\setminus\{0\}\rightarrow \mathbb{R}_{+} \), we show that the map \( h:X\rightarrow Y \) that satisfies the inequality \( \lVert h(cx+dy)- Ch(x)-Dh(y)\rVert_{\ast}\leq \gamma(x,y) \), is a solution to general linear functional equation for every \( x, y \in X\setminus\{0\} \). Finally, this paper concludes with some consequences of the results.
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The authors are grateful to an anonymous referee for his/her useful suggestions which improved the presentation of this paper.
Funding
This work was supported by the Ministry of Higher Education under Fundamental Research Grant Scheme (FRGS/1/2021/STG06/UTM/02/5). The first author expresses gratitude to the Ministry of higher education of Afghanistan for supporting this research under the program of HEDP.
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Shuja, S., Embong, A.F. & Ali, N.M.M. Hyperstability of the General Linear Functional Equation in Non-Archimedean Banach Spaces. P-Adic Num Ultrametr Anal Appl 16, 70–81 (2024). https://doi.org/10.1134/S2070046624010060
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DOI: https://doi.org/10.1134/S2070046624010060