of arbitrary dimension and with an arbitrary finite set of admissible steps. The potential can
be unbounded and can depend on a few steps of the walk. Directed, undirected, and
stretched polymers, as well as random walk in random environment, are covered. The
restriction needed is on the moment of the potential, in relation to the degree of mixing of the
ergodic environment. We derive two variational formulas for the limiting quenched free …