On a class of nonlocal problems with fractional gradient constraint

We consider a Hilbertian and a charges approach to fractional gradient constraint problems of the type $|D^\sigma u|\leq g$, involving the distributional fractional Riesz gradient $D^\sigma$, $0<\sigma <1$, extending previous results on the existence of solutions and Lagrange multipliers of these nonlocal problems. We also prove their convergence as $\sigma\nearrow1$ towards their local counterparts with the gradient constraint $|D u|\leq g$.