Variational inequalities for the spectral fractional Laplacian

In this paper we study the obstacle problems for the Navier (spectral) fractional Laplacian ${(-{\mathrm{\Delta }}_{\mathrm{\Omega }})}^{\text{\hspace{0.17em}⁣}s}$ of order $s\in (0,1)$, in a bounded domain $\mathrm{\Omega }\subset {\mathbb{R}}^n$.