Special Session 123: 

Moments of the (2+1)-dimensional directed polymer in the critical window

Rongfeng Sun
National University of Singapore
Singapore
Co-Author(s):    F. Caravenna, N. Zygouras
Abstract:
Recently, we have shown that the partition function of the directed polymer model on Z^{2+1} admits a phase transition in a suitable continuum and weak disorder limit. In particular, the partition function converges in law to a log-normal distribution below the critical point, and converges to 0 at and above the critical point. Here we focus on a suitable window around the critical point, and we prove that the space-averaged point-to-plane partition function has a uniformly bounded third moment. As a consequence, when interpreted as a random measure on R^2, the rescaled point-to-plane partition functions have non-trivial limit points, and each limit point has the same explicit covariance structure.