Hydrodynamics of Porous Medium Model with Slow Reservoirs

We analyze the hydrodynamic behavior of the porous medium model (PMM) in a discrete space $$\{0,\ldots , n\}$$, where the sites 0 and n stand for reservoirs. Our strategy relies on the entropy method of Guo et al. (Commun Math Phys 118:31–59, 1988). However, this method cannot be straightforwardly applied, since there are configurations that do not evolve according to the dynamics (blocked configurations). In order to avoid this problem, we slightly perturbed the dynamics in such a way that the macroscopic behavior of the system keeps following the porous medium equation (PME), but with boundary conditions which depend on the reservoirs' strength.