A refined estimate of the grazing limit from Boltzmann to Landau operator in Coulomb potential

High order approximation for the Boltzmann equation without angular cutoff under moderately soft potentials

“…It may be possible to reduce the regularity H 5 to H 3 as the highest derivative order is 3 in [10]. In this regard, one may see [47] for details. It is not clear how to reduce the regularity furthermore if one needs to use the grazing limit result from Boltzmann to Landau.…”