Building stable stellar systems with rho as the only datum

CARPINTERO, D.

Rio de Janeiro, Brasil

Congreso; XXVII General Assembly - IAU; 2009

Unión Astronómica Internacional

One of the most popular methods to realize a stable stellar system with a set of N particles is the Schwarzschild algorithm, in which a library of wisely chosen orbits is linearly expanded in order to simulate the overall system density: the initial conditions of those orbits become then a fair sample of the phase-space distribution of the system. This method owes its popularity to the fact that, in principle, it does not require the system to have any particular symmetry, although some troubles have been reported when chaotic regions are included. The only weak spot is the correct selection of the initial library of orbits: it has to contain orbits of all types allowable by the system at all possible energies, that is, the library itself must be a fair sample of possible orbits, which means a thorough a priori knowledge of the system to be simulated. Genetic algorithms, being capable of inspect large multidimensional spaces, allow the building of such a library without any previous analysis of the dynamical properties of the stellar system being simulated.