Tanaka Theorem for Inelastic Maxwell Models
  We show that the Euclidean Wasserstein distance is contractive for inelastic homogeneous Boltzmann kinetic equations in the Maxwellian approximation and its associated Kac-like caricature. This property is as a generalization of the Tanaka theorem to inelastic interactions. Consequences are drawn on the asymptotic behavior of solutions in terms only of the Euclidean Wasserstein distance. 
Fran\c{c}ois Bolley (IMT), Jos\'e Antonio Carrillo (UAB)