Global hypoelliptic and symbolic estimates for the linearized Boltzmann   operator without angular cutoff
  In this article we provide global subelliptic estimates for the linearized inhomogeneous Boltzmann equation without angular cutoff, and show that some global gain in the spatial direction is available although the corresponding operator is not elliptic in this direction. The proof is based on a multiplier method and the so-called Wick quantization, together with a careful analysis of the symbolic properties of the Weyl symbol of the Boltzmann collision operator. 
Radjesvarane Alexandre (USTH), Fr\'ed\'eric H\'erau (LMJL), Wei-Xi Li
math.AP