Landau linearized operator and hypoellipticity
  We consider the linearized Landau operator for which we provide simple proofs of hypoellipticity, and in particular we recover the recent results of H\' erau and Pravda-Starov \cite{herau-all}. Our arguments are elementary and in particular avoids any use of pseudo-differential calculus. 
Radjesvarane Alexandre (IRENAV)
math.AP