Esposito R., Marra R., Yau H.T.
Navier-Stokes equations for a stochastic 
particle systems on the lattice
(502K, Postscript)

ABSTRACT.  We introduce a class of stochastic models  of particles 
on the cubic lattice $\Bbb Z^d$ with velocities and study the
hydrodynamical limit on the diffusive space-time scale.  
Assuming special initial conditions corresponding to the 
incompressible regime, we prove that in dimension $d\ge 3$ 
there is a law of large numbers for the empirical density and
the  rescaled empirical velocity field. Moreover the limit 
fields satisfy the  corresponding incompressible Navier-Stokes 
equations,with viscosity matrices characterized by a variational 
formula, formally equivalent to the Green-Kubo formula.