... Rd Assume that the Cauchy problem for the mean field equation ôf(t, z) + div. f(t, z) s K(z, z ... (Z1, ..., zi) + X. divo, s K(zi,zi+1)s; H (Z1, ..., z -1)dź -1 = 0 l=1 R4 for all j > 1. Proof Since f is of class C" at least, one has j j off ...