A nonlinear diffusion equation is considered, where the nonlinearity arises due to the variation of the diffusion coefficient with concentration. If this diffusion coefficient vanishes at a certain value of the concentration, this produces a number of interesting interfacial effects, such as the finite propagation speed of interfaces (in contrast to the infinite propagation speed of linear diffusion) and waiting-time behavior (in which the interfaces can remain stationary for a finite time before beginning to move). A relatively simple singular perturbation analysis is given to explain these effects.
ASJC Scopus subject areas
- Statistical and Nonlinear Physics
- Mathematical Physics
- Condensed Matter Physics
- Applied Mathematics