Session 23. Nonlinear Evolution Equations and their Applications

Long-time behavior for a simplified Keller-Rubinov model for Liesegang rings in the fast reaction limit

Marcel Oliver, Jacobs University, Germany
Liesegang rings are regular patterns in a chemical precipation reaction which typically follow power laws in the spacing of width and distance. Among several mathematical models, the Keller--Rubinov model [3] is a reaction-diffusion equation with a super-saturation threshold in the reaction term. Hilhorst et al. [2,1] study the fast reaction limit in which, among other assumptions, the reaction rate of the initial step of the mechanism is assumed to be infinitely fast. As a result, the Keller--Rubinov model reduces to a single reaction-diffusion equation with a singular driving term and a reaction term involving memory and thresholding.

As in [1], we consider the one-dimensional situation, which we shall refer to as the HHMO model. Noting that the HHMO model possesses a self-similar solution that is explicitly expressable in terms of special fuctions, we present numerical evidence as well as a mechanism derived from a simplifed version of the system which indicate that the self-similar profile is ``super-attracting'' in the sense that solutions to the HHMO model tend to the self-similar profile in a finite time. We then re-interpret the self-similar profile as a precipitation density function.

References
  1. D. Hilhorst, R. van der Hout, M. Mimura, and I. Ohnishi, A mathematical study of the one-dimensional Keller and Rubinow model for Liesegang bands , J. Stat. Phys. 135, 2009, 107-132.
  2. D. Hilhorst, R. van der Hout, and L.A. Peletier, The fast reaction limit for a reaction-diffusion system , J. Math. Anal. Appl. 199, 1996, 349-373.
  3. J.B. Keller and S.I. Rubinow, Recurrent precipitation and Liesegang rings , J. Chem. Phys. 74, 1981, 5000-5007.
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