Collective relaxation of stellar systems.
Abstract
The problem of stellar system relaxation is studied from the point of view of ergodic theory, and it is shown that an exponential instability specific to Kolmogorov (1958) K-systems, and leading to equilibrium, exists in general stellar systems. The relation between the exponential divergence of geodesics and the statistical properties of an N-body system is first considered, and a collective relaxation time is defined as the index of the exponential deviation. Following calculation of the manifold scalar curvature, the collective relaxation time is estimated, and its difference from the binary relaxation time is discussed. The existence of three scales of length and time for stellar systems is demonstrated, and it is shown that, in general, the two-dimensional curvature can be both negative and positive, though in spherical systems it is strongly positive.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1986
- Bibcode:
- 1986A&A...160..203G
- Keywords:
-
- Astrodynamics;
- Galactic Rotation;
- Globular Clusters;
- Kolmogoroff Theory;
- Relaxation (Mechanics);
- Stellar Systems;
- Ergodic Process;
- Riemann Manifold;
- Astrophysics