Scaling limit of the discrete Gaussian free field with degenerate random conductances

We consider discrete Gaussian free fields with ergodic random conductances on a class of random subgraphs of ${\mathbb{Z}}^d$, $d\ge 2$, including i.i.d.\ supercritical percolation clusters, where the conductances are possibly unbounded but satisfy a moment condition. As our main result, we show that, for almost every realization of the environment, the rescaled field converges in law towards a continuum Gaussian free field. We also present a scaling limit for the covariances of the field. To obtain the latter, we establish a quenched local limit theorem for the Green’s function of the associated random walk among random conductances with Dirichlet boundary conditions.