Real analyticity of solutions to Schr\"odinger equations involving   fractional Laplacians
  We prove analyticity of solutions in $\mathbb{R}^{n}$, $n\ge1$, to certain nonlocal linear Schr\"odinger equations with analytic potentials. 
Anna Dall'Acqua, S{\o}ren Fournais, Thomas {\O}stergaard S{\o}rensen,   and Edgardo Stockmeyer
math.AP math-ph math.MP