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DOI: 10.5445/IR/1000072745

Entropy decay for the Kac evolution

Bonetto, Federico; Geisinger, Alissa; Loss, Michael; Ried, Tobias

We consider solutions to the Kac master equation for initial conditions where N particles are in a thermal equilibrium and $M \leq \ N$ particles are out of equilibrium. We show that such solutions have exponential decay in entropy relative to the thermal state. More precisely, the decay is exponential in time with an explicit rate that is essentially independent on the particle number. This is in marked contrast to previous results which show that the entropy production for arbitrary initial conditions is inversely proportional to the particle number. The proof relies on Nelson's hypercontractive estimate and the geometric form of the Brascamp-Lieb inequalities due to Franck Barthe. Similar results hold for the Kac-Boltzmann equation with uniform scattering cross sections.

Zugehörige Institution(en) am KIT Institut für Analysis (IANA)
Sonderforschungsbereich 1173 (SFB 1173)
Publikationstyp Forschungsbericht
Jahr 2017
Sprache Englisch
Identifikator ISSN: 2365-662X
URN: urn:nbn:de:swb:90-727450
KITopen-ID: 1000072745
Verlag KIT, Karlsruhe
Umfang 26 S.
Serie CRC 1173 ; 2017/20
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