Rice's ansatz for overdamped Ø4 kinks at finite temperature

Physical Review E 67 027601 (2003)

G.D. Lythe

Department of Applied Mathematics ,
University of Leeds,

Franz Mertens

Physikalisches Institut, Universitat Bayreuth,
D-95440 Bayreuth, Germany.


The dynamics of a kink driven by noise is analysed using the two collective variables of the Rice ansatz: position and width. Starting from a stochastic partial differential equation, with the Ø4 potential in the overdamped limit, the pair of stochastic differential equations for the collective variables are derived without approximation other than the ansatz itself. From the steady state probability density of the kink width, the diffusivity of a kink is calculated.

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