Stability of multi-time step partitioned integrators for first-order finite element systems (Q1080631)

Mixed time integration procedures are considered, especially for diffusion problems. They arise from \(u^ n:=u^{n-1}+(1-\alpha)\Delta tu^{n-1}+\alpha \Delta tu^ n,\) where \(\alpha\) varies in [0,1] and different time steps are conveniently used for subdomains of a finite element mesh. The authors present a sound stability analysis for such procedures.