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Higher order of fully discrete solution for parabolic problems in \(L_\infty\). (English) Zbl 0915.65108

Summary: We approximate the solution of an initial-boundary value problem using a Galerkin-finite element method for the spatial discretization, and implicit Runge-Kutta methods for the time stepping. To deal with the nonlinear term \(f(x,t,u)\), we introduce the well-known extrapolation scheme which was used widely to prove the convergence in \(L_2\)-norm. We present computational results showing that the optimal order of convergence arising under \(L_2\)-norm will be preserved in \(L_\infty\)-norm.

MSC:

65M60 Finite element, Rayleigh-Ritz and Galerkin methods for initial value and initial-boundary value problems involving PDEs
65M06 Finite difference methods for initial value and initial-boundary value problems involving PDEs
65M12 Stability and convergence of numerical methods for initial value and initial-boundary value problems involving PDEs
35K55 Nonlinear parabolic equations