Dirr, Nicolas ORCID: https://orcid.org/0000-0003-3634-7367 and Luckhaus, Stephen 2001. Mesoscopic limit for non-isothermal phase transition. Markov processes and related fields 7 (3) , pp. 355-381. |
Abstract
Motivated by the problem of modeling nucleation in non-isothermal systems, we consider the stochastic evolution of a coupled system of a lattice spin variable $\sigma$ and a continuous variable $e$ (corresponding to the phase and the energy density of a continuum system). The spin variables flip with rates depending both on a Kac potential type interaction with the spins and on an interaction with the $e$-field, which plays the role of the external field in ferromagnetics but evolves by a diffusion equation with a forcing depending on the spins. We analyze the mesoscopic limit, where space scales like the diverging interaction range of the Kac potential, $\gamma^{-1},$ while time is not rescaled. By writing $\sigma$ as random time change of a family of independent spins, and thus reducing the problem to investigating integral equations parametrized by independent random variables, we show that as $\gamma\to 0$ the average of the spins over small cubes and the field $e$ converge in probability to the solution of a system of nonlocal evolution equations which is similar to the phase field equations. In some cases the convergence holds until times of order ${\log(\gamma^{-1})}.$
Item Type: | Article |
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Date Type: | Publication |
Status: | Published |
Schools: | Mathematics |
Subjects: | Q Science > QA Mathematics |
Uncontrolled Keywords: | Non-isothermal phase change; Kac potential; Random time change; Microscopic model for phase field equations |
Publisher: | Polymat |
ISSN: | 1024-2953 |
Related URLs: | |
Last Modified: | 18 Oct 2022 13:13 |
URI: | https://orca.cardiff.ac.uk/id/eprint/13080 |
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