Exact solutions to a Muskat problem with line distributions of sinks and   sources
  The evolution of a two-phase Hele-Shaw problem, a Muskat problem, under assumption of a negligible surface tension is considered. We use the Schwarz function approach and allow the sinks and sources to be line distributions with disjoint supports located in the exterior and the interior domains, a two-phase mother body. We give examples of exact solutions when the interface belongs to a certain family of algebraic curves, defined by the initial shape of the boundary, and the cusp formation does not occur. 
L. Akinyemi, T.V. Savina, and A.A. Nepomnyashchy
math.AP