(2014) 'Domain decomposition preconditioners for discontinuous Galerkin methods for elliptic problems on complicated domains.', Journal of scientic computing., 60 (1). pp. 203-227. Further information on publisher's website:http://dx.doi.org/10.1007/s10915-013-9792-y Publisher's copyright statement:The nal publication is available at Springer via http://dx.doi.org/10.1007/s10915-013-9792-y.Additional information:
Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract. In this article we consider the application of Schwarz-type domain decomposition preconditioners for discontinuous Galerkin finite element approximations of elliptic partial differential equations posed on complicated domains, which are characterized by small details in the computational domain or microstructures. In this setting, it is necessary to define a suitable coarse-level solver, in order to guarantee the scalability of the preconditioner under mesh refinement. To this end, we exploit recent ideas developed in the so-called composite finite element framework, which allows for the definition of finite element methods on general meshes consisting of agglomerated elements. Numerical experiments highlighting the practical performance of the proposed preconditioner are presented.Key words. Composite finite element methods, discontinuous Galerkin methods, domain decomposition, Schwarz preconditioners 1. Introduction. In recent years, considerable attention has been devoted to the development of efficient iterative solvers for the solution of the linear system of equations arising from the discontinuous Galerkin finite element (DGFEM) discretization of a range of model problems. In the framework of two level preconditioners, scalable non-overlapping Schwarz methods have been proposed and analyzed for the h-version of the DGFEM in the articles [21,18,4,5,8,15,9]. More recently, in [6,11], it has been proved that the non-overlapping Schwarz preconditioners can also be successfully employed to reduce the condition number of the stiffness matrices arising from a wide class of high-order DGFEM discretizations of elliptic problems; see, also, [7]. We stress that Schwarz-type preconditioners are particularly suited to DGFEMs, in the sense that uniform scalability of the underlying iterative method may be established without the need to overlap the subdomain partition of the computational mesh. This is a particularly attractive property, since the absence of overlapping subdomains reduces communication between processors on parallel machines. By (uniform) scal...