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In cosmology, Gurzadyan-Savvidy (GS) relaxation is a theory developed by Vahe Gurzadyan and George Savvidy to explain the relaxation over time of the dynamics of N-body gravitating systems such as star clusters and galaxies. Stellar systems observed in the Universe – globular clusters and elliptical galaxies – reveal their relaxed state reflected in the high degree of regularity of some of their physical characteristics such as surface luminosity, velocity dispersion, geometric shapes, etc. The basic mechanism of relaxation of stellar systems has been considered the 2-body encounters, to lead to the observed fine-grained equilibrium. The coarse-grained phase of evolution of gravitating systems is described by violent relaxation developed by Donald Lynden-Bell. The 2-body mechanism of relaxation is known in plasma physics. The difficulties with description of collective effects in N-body gravitating systems arise due to the long-range character of gravitational interaction, as distinct of plasma where due to two different signs of charges the Debye screening takes place. The 2-body relaxation mechanism e.g. for elliptical galaxies predicts around years i.e. time scales exceeding the age of the Universe. The problem of relaxation and evolution of stellar systems and the role of collective effects are studied by various techniques, see. Among the efficient methods of study of N-body gravitating systems are the numerical simulations, particularly, Sverre Aarseth's N-body codes are widely used.
References
- ↑ Heggie, D. C. (1 December 1975). "Binary evolution in stellar dynamics". Monthly Notices of the Royal Astronomical Society. 173 (3): 729–787. Bibcode:1975MNRAS.173..729H. doi: 10.1093/mnras/173.3.729 .
- ↑ "The Gravitational Million-Body Problem: A Multidisciplinary Approach to Star Cluster Dynamics". Cambridge University Press.
- ↑ Megalithic Science: Ancient Mathematics and Astronomy in North-west Europe: Douglas C. Heggie: 9780500272114: Amazon.com: Books. ISBN 0500272115.
- ↑ "George Heriot's School Captains and Duces". george-heriots.com.
- ↑ "IAS Visiting Scholars". www.ias.edu.
- ↑ "Invited Speakers – ANZIAM 2014". anziam2014.auckland.ac.nz.
- ↑ "IAU Commission 37: "Star Clusters and Associations" (Triennium 1985–1988)". iau.org.
