Exact asymptotic results for persistence in the Sinai model with arbitrary drift

We obtain exact asymptotic results for the disorder averaged persistence of a Brownian particle moving in a biased Sinai landscape. We employ a method that maps the problem of computing the persistence to the problem of finding the energy spectrum of a single-particle quantum Hamiltonian, which can be subsequently found. Our method allows us analytical access to arbitrary values of the drift (bias), thus going beyond the previous methods that provide results only in the limit of vanishing drift. We show that on varying the drift the persistence displays a variety of rich asymptotic behaviors including, in particular, interesting qualitative changes at some special values of the drift.