Revista Matemática Iberoamericana


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Volume 21, Issue 3, 2005, pp. 819–841
DOI: 10.4171/RMI/436

Published online: 2005-12-31

Explicit spectral gap estimates for the linearized Boltzmann and Landau operators with hard potentials

Céline Baranger[1] and Clément Mouhot[2]

(1) CMLA-ENS, Cachan, France
(2) Université de Lyon, France

This paper deals with explicit spectral gap estimates for the linearized Boltzmann operator with hard potentials (and hard spheres). We prove that it can be reduced to the Maxwellian case, for which explicit estimates are already known. Such a method is constructive, does not rely on Weyl's Theorem and thus does not require Grad's splitting. The more physical idea of the proof is to use geometrical properties of the whole collision operator. In a second part, we use the fact that the Landau operator can be expressed as the limit of the Boltzmann operator as collisions become grazing in order to deduce explicit spectral gap estimates for the linearized Landau operator with hard potentials.

Keywords: Spectral gap, linearized Boltzmann operator, Landau linearized operator, geometrical properties, explicit, grazing collision limit, hard potentials

Baranger Céline, Mouhot Clément: Explicit spectral gap estimates for the linearized Boltzmann and Landau operators with hard potentials. Rev. Mat. Iberoamericana 21 (2005), 819-841. doi: 10.4171/RMI/436