“…The properties of the restricted Dirichlet fractional Laplacian defined in the introduction were studied e.g. in Blumenthal and Getoor , Landkof , Hoh and Jacob , Kulczycki , Chen and Song , Jakubowski , Silvestre , Caffarelli and Silvestre , Frank and Geisinger , Ros‐Oton and Serra , , Felsinger, Kassmann and Voigt , Grubb , , Bonforte, Sire and Vazquez , Servadei and Valdinoci , Binlin, Molica Bisci and Servadei , and many more papers referred to in these works (see in particular the list in ).…”