Jérémie Szeftel

2papers

2 Papers

NAJun 14, 2010
Optimized Schwarz waveform relaxation and discontinuous Galerkin time stepping for heterogeneous problems

Laurence Halpern, Jérémie Szeftel, Caroline Japhet

We design and analyze a Schwarz waveform relaxation algorithm for domain decomposition of advection-diffusion-reaction problems with strong heterogeneities. The interfaces are curved, and we use optimized Robin or Ventcell transmission conditions. We analyze the semi-discretization in time with Discontinuous Galerkin as well. We also show two-dimensional numerical results using generalized mortar finite elements in space.

NAJan 31, 2007
Nonlinear Nonoverlapping Schwarz Waveform Relaxation for Semilinear Wave Propagation

Laurence Halpern, Jérémie Szeftel

We introduce a non-overlapping variant of the Schwarz waveform relaxation algorithm for semilinear wave propagation in one dimension. Using the theory of absorbing boundary conditions, we derive a new nonlinear algorithm. We show that the algorithm is well-posed and we prove its convergence by energy estimates and a Galerkin method. We then introduce an explicit scheme. We prove the convergence of the discrete algorithm with suitable assumptions on the nonlinearity. We finally illustrate our analysis with numerical experiments.