  The Boltzmann H-theorem implies that the solution to the Boltzmann equation
tends to an equilibrium, that is, a Maxwellian when time tends to infinity.
This has been proved in varies settings when the initial energy is finite.
However, when the initial energy is infinite, the time asymptotic state is no
longer described by a Maxwellian, but a self-similar solution obtained by
Bobylev-Cercignani. The purpose of this paper is to rigorously justify this for
the spatially homogeneous problem with Maxwellian molecule type cross section
without angular cutoff.
