“…Briefly, the time dependence of the process brings about a strong time degeneracy of the underlying Dirichlet form, which satisfies no sector condition, even weak. To face such a degeneracy, analytical methods, more precisely compactness methods, carried through the homogenization procedure for a uniformly elliptic diffusion matrix a in periodic media [1,20] or in random media [4]. In [8], critical scaling is considered (α = 2 and β = 1) and an annealed invariance principle is proved for the diffusion (1) by means of probabilistic tools under the assumptions V = 0 and a = Id.…”