An improved and generalized theory for the collisional evolution of Keplerian systems

Abstract

A calculation of collisional integrals with a higher accuracy yields excellent agreement between computer simulations and the collisional theory of Keplerian systems. Inclusion of axial rotation of particles modifies the evolution but does not introduce qualitatively new phenomena. Friction between the particles has a stabilizing influence, while deviations from an exactly spherical shape produce an opposite effect. The rotation of spherical or irregular bodies cannot prevent a final flattening of the system into a monolayer without also causing its disintegration. Computer simulations with a small number of particles do not represent the typical collisional evolution. They provide a test for the theory, but may sometimes lead to a misinterpretation of astronomical phenomena.