### Abstract

We introduce an asymmetric classical Ginzburg-Landau model in a bounded interval, and study its dynamical behavior when perturbed by weak spatiotemporal noise. The Kramers escape rate from a locally stable state is computed as a function of the interval length. An asymptotically sharp second-order phase transition in activation behavior, with corresponding critical behavior of the rate prefactor, occurs at a critical length ℓ_{c}, similar to what is observed in symmetric models. The weak-noise exit time asymptotics, to both leading and subdominant orders, are analyzed at all interval lengthscales. The divergence of the prefactor as the critical length is approached is discussed in terms of a crossover from non-Arrhenius to Arrhenius behavior as noise intensity decreases. More general models without symmetry are observed to display similar behavior, suggesting that the presence of a "phase transition" in escape behavior is a robust and widespread phenomenon.

Original language | English (US) |
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Pages (from-to) | 1537-1556 |

Number of pages | 20 |

Journal | Journal of Statistical Physics |

Volume | 114 |

Issue number | 5-6 |

State | Published - Mar 1 2004 |

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### Keywords

- Droplet nucleation
- False vacuum
- Fluctuation determinant
- Fokker-Planck equation
- Instanton
- Non-Arrhenius behavior
- Spatiotemporal noise
- Stochastic escape problem
- Stochastic exit problem
- Stochastically perturbed dynamical systems

### ASJC Scopus subject areas

- Statistical and Nonlinear Physics
- Mathematical Physics

### Cite this

*Journal of Statistical Physics*,

*114*(5-6), 1537-1556.