Abstract
We prove that the solution of the spatially homogeneous Boltzmann equation is bounded pointwise from below by a Maxwellian, i.e. a function of the formc 1 exp(-c 2 v 2). This holds for any initial data with bounded mass, energy and entropy, and for any positive timet≧t 0. The constantsc 1, andc 2, depend on the mass, energy and entropy of the initial data, and ont 0>0 only.
A similar result is obtained for the Kac caricature of the Boltzmann equation, where the proof is easier.
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Communicated by J.L. Lebowitz
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Pulvirenti, A., Wennberg, B. A maxwellian lower bound for solutions to the Boltzmann equation. Commun.Math. Phys. 183, 145–160 (1997). https://doi.org/10.1007/BF02509799
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DOI: https://doi.org/10.1007/BF02509799