Article ID Journal Published Year Pages File Type
978986 Physica A: Statistical Mechanics and its Applications 2009 11 Pages PDF
Abstract

We point out a remarkable analogy between the limiting mass of relativistic white dwarf stars (Chandrasekhar’s limit) and the critical mass of bacterial populations in a generalized Keller–Segel model of chemotaxis [P.H. Chavanis, C. Sire, Phys. Rev. E 69 (2004) 016116]. This model is based on generalized stochastic processes leading to the Tsallis statistics. The equilibrium states correspond to polytropic configurations similar to gaseous polytropes in astrophysics. For the critical index n3=d/(d−2)n3=d/(d−2) (where d≥2d≥2 is the dimension of space), the theory of polytropes leads to a unique value of the mass McMc that we interpret as a limiting mass. In d=3d=3, we find Mc=202.8956…Mc=202.8956… and in d=2d=2, we recover the well-known result Mc=8πMc=8π (in suitable units). For MMcM>Mc, the system collapses and forms a Dirac peak containing a mass McMc surrounded by a halo. This paper exposes the model and shows, by simple considerations, the origin of the critical mass. A detailed description of the critical dynamics of the generalized Keller–Segel model will be given in a forthcoming paper.

Related Topics
Physical Sciences and Engineering Mathematics Mathematical Physics
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