Universality for the pinning model in the weak coupling regime

Francesco Caravenna (1) , Fabio Lucio Toninelli † (2, 3, 4) , Torri Niccolo (2, 4)

1 Dipartimento di Matematica e Applicazioni [Milano]
2 ICJ - Institut Camille Jordan
3 CNRS - Centre National de la Recherche Scientifique
4 PSPM - Probabilités, statistique, physique mathématique

We consider disordered pinning models, when the return time distribution of the underlying renewal process has a polynomial tail with exponent α ∈ (1/2 , 1). This corresponds to a regime where disorder is known to be relevant , that is, to change the critical exponent of the localization transition and to induce a nontrivial shift of the critical point. We show that the free energy and critical curve have an explicit universal asymptotic behavior in the weak coupling regime, depending only on the tail of the return time distribution and not on finer details of the models. This is obtained comparing the partition functions with corresponding continuum quantities, through coarse-graining techniques.

Mots clés: random polymer; universality; coarse-graining; critical curve; free energy; pinning model; disorder relevance; Scaling limit; weak disorder

Domaines: Mathématiques [math]

Francesco Caravenna, Fabio Lucio Toninelli †, Torri Niccolo. Universality for the pinning model in the weak coupling regime. Annals of Probability, 2017, 45 (4), pp.2154-2209. ⟨10.1214/16-AOP1109⟩. ⟨hal-01154945v2⟩