AnL1-existence theorem is proved for the nonlinear stationary Boltzmann equation with hard forces and no small velocity truncation—only the Grad angular cut-off-in a setting between two coaxial rotating cylinders when the indata are given on the cylinders.
"A large data existence result for the stationary Boltzmann equation in a cylindrical geometry." Ark. Mat. 43 (1) 29 - 50, April 2005. https://doi.org/10.1007/BF02383609