%0 Journal Article %A Luis A. Caffarelli %A Jean-Michel Roquejoffre %A Yannick Sire %T Variational problems with free boundaries for the fractional Laplacian %J Journal of the European Mathematical Society %D 2010 %P 1151-1179 %V 12 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4171/jems/226/ %R 10.4171/jems/226 %F JEMS_2010_12_5_a3