POSITIVE SOLUTIONS FOR SINGULAR SEMIPOSITONE NONLINEAR FRACTIONAL DIFFERENTIAL SYSTEM

Abstract

In this paper, under suitable conditions we employ the nonlinear alternative of Leray-Schauder type and the Guo-Krasnoselskii fixed point theorem to show the existence of positive solutions for a system of nonlinear singular Riemann-Liouville fractional differential equations with sign-changing nonlinearities, subject to integral boundary conditions. Some examples are given to illustrate our main results.