Additive average Schwarz method for a Crouzeix-Raviart Finite Volume   Element Discretization of Elliptic Problems with Heterogeneous Coefficients
  In this paper we introduce an additive Schwarz method for a Crouzeix-Raviart Finite Volume Element (CRFVE) discretization of a second order elliptic problem with discontinuous coefficients, where the discontinuities are both inside the subdomains and across and along the subdomain boundaries. We show that, depending on the distribution of the coefficient in the model problem, the parameters describing the GMRES convergence rate of the proposed method depend linearly or quadratically on the mesh parameters $H/h$. Also, under certain restrictions on the distribution of the coefficient, the convergence of the GMRES method is independent of jumps in the coefficient. 
Atle Loneland, Leszek Marcinkowski and Talal Rahman
math.NA