{ "id": "1305.6816", "version": "v1", "published": "2013-05-29T14:23:29.000Z", "updated": "2013-05-29T14:23:29.000Z", "title": "About an H-theorem for systems with non-conservative interactions", "authors": [ "Umberto Marini Bettolo Marconi", "Andrea Puglisi", "Angelo Vulpiani" ], "comment": "15 pages, 4 figures, submitted", "journal": "J. Stat. Mech. (2013) P08003", "doi": "10.1088/1742-5468/2013/08/P08003", "categories": [ "cond-mat.stat-mech" ], "abstract": "We exhibit some arguments in favour of an H-theorem for a generalization of the Boltzmann equation including non-conservative interactions and a linear Fokker-Planck-like thermostatting term. Such a non-linear equation describing the evolution of the single particle probability $P_i(t)$ of being in state $i$ at time $t$, is a suitable model for granular gases and is indicated here as Boltzmann-Fokker-Planck (BFP) equation. The conjectured H-functional, which appears to be non-increasing, is $H_C(t)=\\sum_i P_i(t) \\ln P_i(t)/\\Pi_i$ with $\\Pi_i = \\lim_{t \\to \\infty} P_i(t)$, in analogy with the H-functional of Markov processes. The extension to continuous states is straightforward. A simple proof can be given for the elastic BFP equation. A semi-analytical proof is also offered for the BFP equation for so-called inelastic Maxwell molecules. Other evidence is obtained by solving particular BFP cases through numerical integration or through \"particle schemes\" such as the Direct Simulation Monte Carlo.", "revisions": [ { "version": "v1", "updated": "2013-05-29T14:23:29.000Z" } ], "analyses": { "keywords": [ "non-conservative interactions", "direct simulation monte carlo", "elastic bfp equation", "single particle probability", "inelastic maxwell molecules" ], "tags": [ "journal article" ], "publication": { "journal": "Journal of Statistical Mechanics: Theory and Experiment", "year": 2013, "month": "Aug", "volume": 2013, "number": 8, "pages": "08003" }, "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013JSMTE..08..003M" } } }