A real analytic family of fundamental solutions of elliptic partial   differential operators with real constant coefficients
  We construct of a family of fundamental solutions for elliptic partial differential operators with real constant coefficients. The elements of such a family are expressed by means of jointly real analytic functions of the coefficients of the operators and of the spatial variable. We show regularity properties in the frame of Schauder spaces for the corresponding single layer potentials. 
Matteo Dalla Riva
math.AP