Problems of Collisional Stellar Dynamics

TL;DR

This paper reviews the progress in collisional stellar dynamics since Chandrasekhar's foundational work, emphasizing the role of few-body interactions and dynamical friction in star clusters and related systems.

Contribution

It connects Chandrasekhar's original discoveries with recent advances in understanding collisional stellar systems over the past 50 years.

Findings

Enhanced understanding of dynamical friction effects

Progress in modeling star cluster evolution

Insights into few-body interaction dynamics

Abstract

The discovery of dynamical friction was Chandrasekhar's best known contribution to the theory of stellar dynamics, but his work ranged from the few-body problem to the limit of large N (in effect, galaxies). Much of this work was summarised in the text "Principles of Stellar Dynamics" (Chandrasekhar 1942, 1960), which ranges from a precise calculation of the time of relaxation, through a long analysis of galaxy models, to the behaviour of star clusters in tidal fields. The later edition also includes the work on dynamical friction and related issues. In this review we focus on progress in the collisional aspects of these problems, i.e. those where few-body interactions play a dominant role, and so we omit further discussion of galaxy dynamics. But we try to link Chandrasekhar's fundamental discoveries in collisional problems with the progress that has been made in the 50 years since the publication of the enlarged edition.