Dynamics of a self-gravitating neutron source

Postcollapse dynamics of self-gravitating Brownian particles and bacterial populations.

We address the postcollapse dynamics of a self-gravitating gas of Brownian particles in D dimensions in both canonical and microcanonical ensembles. In the canonical ensemble, the postcollapse evolution is marked by the formation of a Dirac peak with increasing mass. The density profile outside the peak evolves self-similarly with decreasing central density and increasing core radius. In the mi...

Stochastic Dynamics Toward the Steady State of Self-Gravitating Systems

Critical dynamics of self-gravitating Langevin particles and bacterial populations.

We study the critical dynamics of the generalized Smoluchowski-Poisson system (for self-gravitating Langevin particles) or generalized Keller-Segel model (for the chemotaxis of bacterial populations). These models [P. H. Chavanis and C. Sire, Phys. Rev. E 69, 016116 (2004)] are based on generalized stochastic processes leading to the Tsallis statistics. The equilibrium states correspond to poly...

Dynamics of a Self–gravitating Magnetized Source. Received Day Month Year Revised Day Month Year Communicated by Managing Editor

We consider a magnetized degenerate gas of fermions as the matter source of a homogeneous but anisotropic Bianchi I spacetime with a Kasner–like metric. We examine the dynamics of this system by means of a qualitative and numerical study of Einstein-Maxwell field equations which reduce to a non–linear autonomous system. For all initial conditions and combinations of free parameters the gas evol...

Self–gravitating cosmic rings

The classical Einstein–Maxwell field equations admit static horizonless wormhole solutions with only a circular cosmic string singularity. We show how to extend these static solutions to exact rotating asymptotically flat solutions. For a suitable range of parameter values, these solutions describe charged or neutral rotating closed cosmic strings, with a perimeter of the order of their Schwarz...