Project 1: Effective Interface Models with Gradient Interactions and the Cauchy-Born Rule at Positive Temperature

Participants

Jean-Dominique Deuschel, Stephan Luckhaus, Stefan Müller

Summary

We wish to study scalar gradient Gibbs models and atomistic models of nonlinear elasticity. For scalar gradient Gibbs models at moderate $\beta$ we achieved a good understanding of the static properties in the last funding period and we now plan to address questions related to dynamics, in particular hydrodynamic limits and their relation with large deviations and fluctuations. A more ambitious goal is to understand these also at large $\beta$, where the free energy is not everywhere strictly convex. Regarding elasticity models we will extend the renormalization analysis initiated in the last period to the study of correlation functions and to address the uniqueness of the ergodic gradient Gibbs measure. Two rather ambitious long term goals are to explore a possible extension of the renormalization approach beyond perturbation around a free field and the study of more complex structures which arise, e.g., in twinning of crystals.

Achievements of the research group (funding period 2006/08):

  • C. Cotar, J.-D. Deuschel and S. Müller:
  • Strict convexity of the free energy for non-convex gradient models at moderate $\beta$
    Comm. Math. Phys., to appear
    preprint

  • C.Cotar and J.-D. Deuschel:
  • Decay of covariances, uniqueness of ergodic component and scaling limit for a class of $\nabla\phi$ systems with non-convex potential
    preprint

  • F. Caravenna and J.-D. Deuschel:
  • Scaling limits of (1+1)-dimensional pinning models with Laplacian interaction
    preprint

  • F. Caravenna and J.-D. Deuschel:
  • Pinning and wetting transition for (1+1)-dimensional fields with Laplacian interaction
    Ann. Probab., to appear.
    preprint