Extremal solutions for nonlinear fractional boundary value problems with pp-Laplacian

In this paper we investigate the existence and uniqueness of extremal solutions for nonlinear boundary value problems of a fractional pp-Laplacian differential equation involving Riemann–Liouville derivatives. We construct two well-defined monotone iterative sequences of upper and lower solutions which converge uniformly to the actual solution of the problem. A numerical iterative scheme is also introduced to obtain an accurate approximate solution for the problem and an example is presented to illustrate the results.