“…Recently, Caffarelli and Silvestre [16] developed a local interpretation of the fractional Laplacian given in R N by considering a Neumann type operator in the extended domain R N +1 + defined by {(x, t) ∈ R N +1 : t > 0}. A similar extension, for nonlocal problems on bounded domain with the zero Dirichlet boundary condition, was established, for instance, by Cabrè and Tan in [15], Tan [37], Capella, Dàvila, Dupaigne and Sire [17], Brändle, Colorado, de Pablo and Sànchez [13]. It is worth noticing that, in a bounded domain, the Fourier definition of the fractional laplacian and its local Caffarelli-Silvestre interpretation do not agree, see the discussion developed [32] for more details.…”