A short proof of diffusivity for the directed polymers in the weak disorder phase
Hubert Lacoin
Abstract
We provide a new short and elementary proof of diffusivity for directed polymer in a random environment in the weak disorder phase.
Hubert Lacoin
We provide a new short and elementary proof of diffusivity for directed polymer in a random environment in the weak disorder phase.
This paper contains 11 sections, 4 theorems, 26 equations.
Proposition A
We have the following equivalence If $(i)$ and $(ii)$ hold, we further have ${\mathbb P} (W^{\zeta}_{\infty}>0)= {\mathbb P} ( \forall n>0,\ W^\zeta_n>0)$, in particular ${\mathbb P} (W^{\zeta}_{\infty}>0)=1$, if ${\mathbb P} (\zeta_{k,x}>0)=1$.