Realizations of Differential Operators on Conic Manifolds with Boundary
  We study the closed extensions (realizations) of differential operators subject to homogeneous boundary conditions on weighted L_p-Sobolev spaces over a manifold with boundary and conical singularities. Under natural ellipticity conditions we determine the domains of the minimal and the maximal extension. We show that both are Fredholm operators and give a formula for the relative index. 
S. Coriasco, E. Schrohe and J. Seiler