Hyers--Ulam stability, well-posedness, and data dependence for Fisher-type contractive mappings

Nguyễn Hữu Học

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Tóm tắt

In this paper, we investigate Hyers--Ulam stability, well-posedness, and data dependence for mappings satisfying a Fisher-type inequality.
Our stability results are proved in an arbitrary metric space under the sole assumption that a fixed point exists.
A basic ingredient is a structural consequence of the inequality: if $z$ is a fixed point of $T$, then $T^{-1}(\{z\})=\{z\}$.
This unique-preimage property is used to obtain stability estimates with an explicit constant.
As applications, we combine these general results with fixed point existence theorems from \cite{Hoc2022} to derive stability conclusions for boundedly compact, $T$-orbitally compact, and complete metric spaces.
A discontinuous example is included to illustrate the scope of the theory.

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Tài liệu tham khảo

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