On the convergence from Boltzmann to Navier-Stokes-Fourier for general initial data

Pierre Gervais

Published 2022-01-08Version 1

In this work, we prove the convergence of strong solutions of the Boltzman equation, for initial data having polynomial decay in the velocity variable, towards those of the incompressible Navier-Stokes-Fourier system. We show in particular that the solutions of the rescaled Boltzmann equation do not blow up before their hydrodynamic limit does. This is made possible by adapting a strategy introduced by M. Briant, S. Merino and C. Mouhot of writing the solution to the Boltzmann equation as the sum a part with polynomial decay and a second one with Gaussian decay. The Gaussian part is treated with an approach reminiscent of the one used by I. Gallagher and I. Tristani.