View Related Documents

Abstract

We study the dynamics of pattern formation in the one-dimensional partial differential equation
uu - (W¢(ux ))x - uxxt + u = 0\text (u = u(x,t),\text x Î (0,1),\text t > 0)u_u - (W'(u_x ))_x - u_{xxt} + u = 0{\text{ (}}u = u(x,t),{\text{ }}x \in (0,1),{\text{ }}t > 0)
proposed recently by Ball, Holmes, James, Pego & Swart [BHJPS] as a mathematical E[u,ut ] = ò01 (\fracut2 2 + W(ux ) + \fracu2 2)dx.E[u,u_t ] = \int\limits_0^1 {(\frac{{u_t^2 }}{2} + W(u_x ) + \frac{{u^2 }}{2})dx.}
Our analysis of the dynamics confirms the following surprising and striking difference between statics and dynamics, conjectured in [BHJPS] on the basis of numerical simulations of Swart & Holmes [SH]:
–  bullWhile minimizing the above energy predicts infinitely fine patterns (mathematically: weak but not strong convergence of all minimizing sequences (u nvn) of E[u,v] in the Sobolev space W 1 p(0, 1)×L2(0,1)), solutions to the evolution equation of ball et al. typically develop patterns of small but finite length scale (mathematically: strong convergence in W 1 p(0,1)×L2(0,1) of all solutions (u(t),ut(t)) with low initial energy as time t rarr infin).
Moreover, in order to understand the finer details of why the dynamics fails to mimic the behaviour of minimizing sequences and how solutions select their limiting pattern, we present a detailed analysis of the evolution of a restricted class of initial data — those where the strain field u x has a transition layer structure; our analysis includes proofs that
–  bullat low energy, the number of phases is in fact exactly preserved, that is, there is no nucleation or coarsening
–  bulltransition layers lock in and steepen exponentially fast, converging to discontinuous stationary sharp interfaces as time t rarr infin
–  bullthe limiting patterns — while not minimizing energy globally — are lsquorelative minimizersrsquo in the weak sense of the calculus of variations, that is, minimizers among all patterns which share the same strain interface positions.
Communicated by the Editor

Fulltext Preview

Image of the first page of the fulltext document

Frequently asked questions General info on journals and books Send us your feedback Impressum Contact us

© Springer, Part of Springer Science+Business Media Privacy, Disclaimer, Terms & Conditions, and Copyright Info