English

Local limit theorem for directed polymers beyond the $L^2$-phase

Probability 2025-07-03 v3

Abstract

We consider the directed polymer model in the weak disorder phase under the assumption that the partition function is LpL^p-bounded for some p>1+2dp>1+\frac{2}d. We prove that the point-to-point partition function can be approximated by two point-to-plane partition functions at the startpoint and endpoint, and in particular that it is LpL^p-bounded as well. Some consequences of this result are also discussed, the most important of which is a local limit theorem for the polymer measure. We furthermore show that the required LpL^p-boundedness holds for some range of β\beta beyond the L2L^2-critical point, and in the whole interior of the weak disorder phase for environments with finite support.

Keywords

Cite

@article{arxiv.2307.05097,
  title  = {Local limit theorem for directed polymers beyond the $L^2$-phase},
  author = {Stefan Junk},
  journal= {arXiv preprint arXiv:2307.05097},
  year   = {2025}
}

Comments

28 pages, 2 Figures. Accepted version

R2 v1 2026-06-28T11:26:51.405Z