Existence and multiplicity of positive solutions for a class of singular fractional nonlocal boundary value problems

In this article, we consider a class of singular fractional differential equations with nonlocal boundary value conditions. The existence and multiplicity of positive solutions are derived by the fixed point index theory, and the nonlinearity f(t,x) may be singular at t=0,1 and x=0. The interesting point is that the existence results are closely associated with the relationship between 1 and the spectral radii corresponding to the relevant linear operators. An example is also given to demonstrate the validity of the main results.