On the spatially homogeneous Landau equation for hard potentials - Part II: H-theorem and applications

We find a lower bound for the entropy dissipation of the spatially homogene ous Landau equation with hard potentials in terms of the entropy itself. We deduce from this explicit estimates on the, speed-of convergence towards e quilibrium for the solution of this equation. In the case of so-called over maxwellian potentials, the convergence is exponential. We also compute a lo wer bound for the spectral gap of the associated linear operator in this se tting.