The self-gravitating systems are formed by particles interacting through gravity. They describe structure formation in the universe. As a consequence of the long range interaction of gravity, they are inhomogeneous even at thermal equilibrium. We study the self-gravitating systems with several kinds of particles and the self-gravitating systems in the presence of the cosmological constant $ Lambda$. We formulate the statistical mechanics and the mean field approach describing the gaseous phase. We explicitely compute the density of particles and thermodynamic quantities. The presence of $ Lambda$ extends the domain of stability of the gaseous phase. Monte Carlo simulations show that the mean field describes the gaseous phase with an excellent accuracy. Scalling law of the self-gravitating systems with several kinds of particles is found. At the critical point the fractal dimension is independant of their composition and is $1.6...$~.
| Identifer | oai:union.ndltd.org:CCSD/oai:tel.archives-ouvertes.fr:hal-00009142 |
| Date | 24 June 2005 |
| Creators | Siebert, Julien |
| Publisher | Université Pierre et Marie Curie - Paris VI |
| Source Sets | CCSD theses-EN-ligne, France |
| Language | French |
| Detected Language | English |
| Type | PhD thesis |
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