positivity

Joint projects underway

  • Optimal perturbations of RK methods (Tihi, David, Inma)
  • Arbitrary order SSP LMMs (Adrian, David)
  • Variable step size SSP LMMs (David, Adrian, Lajos)
    • Can we save computation by varying the step size? If \(h_{FE}\) is constant? If \(h_{FE}\) varies?
    • Can we prove an upper bound on the step size in terms of \(h_{FE}\) when the step size varies?

Interesting topics for collaboration/open problems

  • Internal error propagation for RK methods
    • Which is the optimal Shu-Osher implementation of a method? (to minimize internal error amplification)
  • Effect of time-dependent boundary conditions on SSP analysis
    • Can we prove that the TV of the numerical solution does not grow faster than that of the exact solution if a TVD+SSP discretization is applied?
  • Induced total variation semi-norm
  • Can one produce a finite volume method that will approximate a solution to a partial differential equation which becomes singular at a point and so is no longer of bounded variation?
  • For hyperbolic problems for which there exist solutions, but no viscosity solutions, what does a finite volume scheme produce?