1998/04/08 by Piet Hut, Hut, Piet
Physics and Astronomy · #Astronomy and Astrophysical Research #Scientific Research and Discoveries #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9804089
10 pages, LaTeX, to appear in the proceedings for the International Symposium on Supercomputing, held in Tokyo, Japan, September 1-3, 1997
arxiv created 1998/04/08 · arxiv updated 2009/12/01
Stellar dynamics is almost unreasonably well suited for an implementation in terms of special-purpose hardware. Unlike the case of molecular dynamics, stellar dynamics deals exclusively with a long-range force, gravity, which leads to a computational cost scaling as the square of the number of stars involved. While special tricks can lead to a reduction of this cost from ∼ N2 to ∼ Nlog N in the case of very large particle numbers, such tricks are not suitable for all areas within stellar dynamics. When a stellar system is close to equilibrium, and has a very high density, it still pays to compute all interactions on a star by star basis, even for N=105. Any cNlog N approach would either gloss over the subtle net effects of near-canceling interactions, driving the evolution of such a system, or would carry a prohibitively large coefficient c. This paper presents a brief introduction to the stellar dynamics of dense stellar systems, aimed at researchers using special purpose computers in other branches of physics.