Monotonicity and symmetry of solutions to fractional p-laplacian systems.

In this paper, we study a class of nonlinear nonlocal problems involving the fractional p-Laplacian operator with gradient terms. By using the direct method of moving planes, we prove the symmetry and monotonicity for positive solutions to the fractional p-Laplacian system in bounded domains and in the whole space. In the proof, decay at infinity and boundary estimate are key ingredients. [ABSTRACT FROM AUTHOR]