Positive Solutions for a System of Fractional Integral Boundary Value Problems Involving Hadamard‐Type Fractional Derivatives

In this paper, we use fixed‐point index to study the existence of positive solutions for a system of Hadamard fractional integral boundary value problems involving nonnegative nonlinearities. By virtue of integral‐type Jensen inequalities, some appropriate concave and convex functions are used to depict the coupling behaviors for our nonlinearities f i ( i = 1, 2).