Astronomy and Astrophysics – Astrophysics
Scientific paper
Feb 2005
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2005a%26a...430..771c&link_type=abstract
Astronomy and Astrophysics, v.430, p.771-778 (2005)
Astronomy and Astrophysics
Astrophysics
8
Galaxy: Kinematics And Dynamics, Gravitation, Stellar Dynamics
Scientific paper
We describe the dynamical evolution of collisionless stellar systems on a coarse-grained scale. We first discuss the statistical theory of violent relaxation, following the seminal paper of Lynden-Bell (\cite{Lynden67}). Consistently with this statistical approach, we present kinetic equations for the coarse-grained distribution function /line{f}({r},{v},t) based on a Maximum Entropy Production Principle or on a quasi-linear theory of the Vlasov-Poisson system. Then, we develop a deterministic approach where the coarse-grained distribution function is defined as a convolution of the fine-grained distribution function f({r},{v},t) by a Gaussian window. We derive the dynamical equation satisfied by /line{f}({r},{v},t) and show that its stationary states are different from those predicted by the statistical theory of violent relaxation. This implies that the notion of coarse-graining must be defined with care. We apply these results to the HMF (Hamiltonian Mean Field) model and find that the spatial density is similar to a Tsallis q-distribution where the q parameter is related to the resolution length.
Bouchet Freddy
Chavanis Pierre-Henri
No associations
LandOfFree
On the coarse-grained evolution of collisionless stellar systems does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with On the coarse-grained evolution of collisionless stellar systems, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the coarse-grained evolution of collisionless stellar systems will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1744762