Abstract:
We investigate the existence and multiplicity of positive solutions for the nonlinear fractional differential equation initial value problem D(0+)(alpha)u(t) + D(0+)(beta)u(t) = f(t, u(t)), u(0) = 0, 0 < t < 1, where 0 < beta < alpha < 1, D-0+(alpha) is the standard Riemann-Liouville differentiation and f : [0,1] x [0,infinity) -> [0,infinity) is continuous. By using some fixed-point results on cones, some existence and multiplicity results of positive solutions are obtained.