SYSTEMS OF NONLINEAR DELAY INTEGRAL EQUATIONS: POSITIVE SOLUTIONS, COMPARISON THEOREMS, AND DATA DEPENDENCE

In this paper, a system of nonlinear delay integral equations related to the spread of certain infectious diseases is investigated. Namely, using Perov’s fixed-point theorem, we obtain sufficient conditions for which the system admits a unique positive solution, and provide a numerical algorithm that converges to this solution. Moreover, we establish some comparison theorems, and study the data dependence of solutions.