N-body simulations are widely used to simulate the dynamical evolution of a variety of systems, among them star clusters.
Much of our understanding of their evolution rests on the results of such direct N-body simulations. They provide insight
in the structural evolution of star clusters, as well as into the occurrence of stellar exotica. Although the major pure N-body
codes STARLAB/KIRA and NBODY4 are widely used for a range of applications, there is no thorough comparison study yet.
we thoroughly compare basic quantities as derived from simulations performed either with STARLAB/KIRA or NBODY4.
a large number of star cluster models for various stellar mass function settings (but without stellar/binary evolution, primordial
binaries, external tidal fields, etc.), evolve them in parallel with STARLAB/KIRA and NBODY4, analyse them in a consistent
way and compare the averaged results quantitatively. For this quantitative comparison, we develop a bootstrap algorithm for
We find an overall excellent agreement between the codes, both for the clusters' structural and
energy parameters as well as for the properties of the dynamically created binaries. However, we identify small differences,
like in the energy conservation before core collapse and the energies of escaping stars, which deserve further studies.
results reassure the comparability and the possibility to combine results from these two major N-body codes, at least for
the purely dynamical models (i.e. without stellar/binary evolution) we performed. Further detailed comparison studies for
more complex systems, e. g. including stellar/binary evolution, are required.