Stability analysis through the Bielecki metric to nonlinear fractional integral equations of $n$-product operators

This work is devoted to the analysis of Hyers, Ulam, and Rassias types of stabilities for nonlinear fractional integral equations with $n$-product operators. In some special cases, our considered integral equation is related to an integral equation which arises in the study of the spread of an infectious disease that does not induce permanent immunity. $n$-product operators are described here in the sense of Riemann-Liouville fractional integrals of order ${\sigma }_i\in (0,1]$ for $i\in \{1,2,\dots ,n\}$. Sufficient conditions are provided to ensure Hyers-Ulam, $\lambda$-semi-Hyers-Ulam, and Hyers-Ulam-Rassias stabilities in the space of continuous real-valued functions defined on the interval $[0,a]$, where $0<a<\mathrm{\infty }$. Those conditions are established by applying the concept of fixed-point arguments within the framework of the Bielecki metric and its generalizations. Two examples are discussed to illustrate the established results.