One-dimensional random field Kac's model: localization of the phases.

Marzio Cassandro (1) , Enza Orlandi (2) , Pierre Picco (3, 4) , Maria Eulalia Vares (5)

1 Dipartimento di Fisica [Roma La Sapienza]
2 Dipartimento di Matematica [Roma TRE]
3 CPT - Centre de Physique Théorique - UMR 6207
4 CPT - Centre de Physique Théorique - UMR 7332
5 CBPF - CBPF

We study the typical profiles of a one dimensional random fieldKac model, for values of the temperature and magnitude of thefield in the region of the two absolute minima for the freeenergy of the corresponding random field Curie Weiss model.We show that, for a set of realizations of the random field of overwhelming probability, the localization of the two phasescorresponding to the previous minima is completely determined.Namely, we are able to construct random intervals tagged with a sign, where typically, with respect to the infinite volume Gibbs measure, the profile is rigid and takes, according to the sign, one of the two values corresponding to the previous minima.Moreover, we characterize the transition from one phase to the other.

Mots clés: random environment; Kac potential; phase transition; random walk; Kac potential.

Domaines: Probabilités [math.PR]

Marzio Cassandro, Enza Orlandi, Pierre Picco, Maria Eulalia Vares. One-dimensional random field Kac's model: localization of the phases.. 2004. ⟨hal-00001128⟩