Fast rate of dead core for fast diffusion equation with strong absorption (Q972028)

The authors investigate the dead core problem for a fast diffusion equation with strong absorption and positive boundary values. They prove that the dead core rate is faster than the one given by the corresponding ODE, which is contrary to the known results for the related extinction, quenching and blow up problems. In their proofs, they combine the method of self-similar variables with some sharp estimates of the solution to the problem considered.