Function spaces and extension results for nonlocal Dirichlet problems
  We study function spaces and extension results in relation with Dirichlet problems involving integrodifferential operators. For such problems, data are prescribed on the complement of a given domain in the Euclidean space. We introduce a function space that serves as a trace space for nonlocal Dirichlet problems and study related extension results. 
Moritz Kassmann, Bartlomiej Dyda
math.AP