Paper Information

The dynamics of a kink driven by noise is analyzed using the two collective variables of the Rice ansatz: position and width. Starting from a stochastic partial differential equation, with the phi(4) 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.