{ "id": "1009.2884", "version": "v3", "published": "2010-09-15T10:02:39.000Z", "updated": "2011-07-25T17:02:49.000Z", "title": "Exact analytical solution of the collapse of self-gravitating Brownian particles and bacterial populations at zero temperature", "authors": [ "Pierre-Henri Chavanis", "Clément Sire" ], "journal": "Phys. Rev. E 83, 031131 (2011)", "doi": "10.1103/PhysRevE.83.031131", "categories": [ "cond-mat.stat-mech", "q-bio.QM" ], "abstract": "We provide an exact analytical solution of the collapse dynamics of self-gravitating Brownian particles and bacterial populations at zero temperature. These systems are described by the Smoluchowski-Poisson system or Keller-Segel model in which the diffusion term is neglected. As a result, the dynamics is purely deterministic. A cold system undergoes a gravitational collapse leading to a finite time singularity: the central density increases and becomes infinite in a finite time t_coll. The evolution continues in the post collapse regime. A Dirac peak emerges, grows and finally captures all the mass in a finite time t_end, while the central density excluding the Dirac peak progressively decreases. Close to the collapse time, the pre and post collapse evolution is self-similar. Interestingly, if one starts from a parabolic density profile, one obtains an exact analytical solution that describes the whole collapse dynamics, from the initial time to the end, and accounts for non self-similar corrections that were neglected in previous works. Our results have possible application in different areas including astrophysics, chemotaxis, colloids and nanoscience.", "revisions": [ { "version": "v3", "updated": "2011-07-25T17:02:49.000Z" } ], "analyses": { "subjects": [ "05.90.+m", "05.40.-a", "47.20.-k", "05.70.-a" ], "keywords": [ "exact analytical solution", "self-gravitating brownian particles", "bacterial populations", "zero temperature", "finite time" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Physical Review E", "year": 2011, "month": "Mar", "volume": 83, "number": 3, "pages": "031131" }, "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011PhRvE..83c1131C" } } }