Multiple positive solutions to systems of nonlinear semipositone fractional differential equations with coupled boundary conditions

摘要

In this paper, we consider a four-point coupled boundary value problem for systems of the nonlinear semipositone fractional differential equation egin{gather*}left{ egin{array}{ll} mathbf{D}_{0+}^lpha u+lambda f(t,u,v)=0,quad 0