  For the random walk among random conductances, we prove that the environment
viewed by the particle converges to equilibrium polynomially fast in the
variance sense, our main hypothesis being that the conductances are bounded
away from zero. The basis of our method is the establishment of a Nash
inequality, followed either by a comparison with the simple random walk or by a
more direct analysis based on a martingale decomposition. As an example of
application, we show that under certain conditions, our results imply an
estimate of the speed of convergence of the mean square displacement of the
walk towards its limit.
