ABSTRACT:

We consider a system of (an)harmonic oscillators perturbed by a noise conserving energy or energy and momentum. In the harmonic case, the model is exactly solvable and we compute Green-Kubo formula for the conductivity. It turns out that the conductivity is finite in dimension $d\geq 3$ but is infinite if $d=1,2$ and momentum is conserved. In the anharmonic case, we obtain upper bounds.
(joint work with G. Basile and S.Olla)