Z d -extensions of probability-preserving dynamical systems are themselves dynamical systems preserving an infinite measure, and generalize random walks. Using the method of moments, we prove a generalized central limit theorem for additive functionals of the extension of integral zero, under spectral assumptions. As a corollary, we get the fact that Green-Kubo's formula is invariant under induction. This allows us to relate the hitting probability of sites with the symmetrized potential kernel, giving an alternative proof and generalizing a theorem of Spitzer. Finally, this relation is used to improve in turn the asumptions of the generalized central limit theorem. Applications to Lorentz gases in finite horizon and to the geodesic flow on abelian covers of compact manifolds of negative curvature are discussed. arXiv:1702.06625v2 [math.DS] 16 May 2017 POTENTIAL KERNEL, HITTING PROBABILITIES AND DISTRIBUTIONAL ASYMPTOTICS 2 observables need only to decay polynomially at infinity, instead of having bounded support. We apply it to the geodesic flow on abelian covers of compact manifolds with negative curvature.This article is organized as follow. We present our setting and our results in Section 1, as well as our applications to Lorentz gases (Sub-subsection 1.4.1) and to geodesic flows (Sub-subsection 1.4.2). In Section 2 we present our spectral assumptions, and prove Theorem 1.4 using the method of moments. In Section 3 we prove Theorems 1.7 and 1.11, and in Section 4 the two applications mentioned above. We discuss Green-Kubo's formula in the Appendix.