Irreversibility in Small Stellar Dynamical Systems.

Abstract

view Abstract Citations (157) References (6) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Irreversibility in Small Stellar Dynamical Systems. Miller, R. H. Abstract Irreversibility in stellar dynamical systems was studied by means of numerical experiments using n-body calculations carried out in a computer for n up to 32. In the experiments, two similar systems evolve simultaneously and the separation of their representative points in phase space was observed to grow exponentially with the time variable because of the effects of encounters. The time constant of this exponential growth defines a relaxation time different from the usual relaxation time of stellar dynamics. Certain properties of the calculation and comparisons of the observed values of this relaxation time with values expected on the basis of binary collisions led to the conclusion that n-body systems with inverse-square law forces behave as tightly coupled systems. The time constant is surprisingly short- about 4r/n, where r is the mean time between binary collisions of one particle. Hard spheres or potentials do not show the collective behavior of inverse-square law systems. Errors in calculations of n-body systems grow exponentially with the time through this mechauism, and may therefore invalidate the results of n-body calculations. Publication: The Astrophysical Journal Pub Date: July 1964 DOI: 10.1086/147911 Bibcode: 1964ApJ...140..250M full text sources ADS |