Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Hybrid N-Body Code Incorporating Algorithmic Regularization and
  Post-Newtonian Forces   We describe a novel N-body code designed for simulations of the central
regions of galaxies containing massive black holes. The code incorporates
Mikkola's 'algorithmic' chain regularization scheme including post-Newtonian
terms up to PN2.5 order. Stars moving beyond the chain are advanced using a
fourth-order integrator with forces computed on a GRAPE board. Performance
tests confirm that the hybrid code achieves better energy conservation, in less
elapsed time, than the standard scheme and that it reproduces the orbits of
stars tightly bound to the black hole with high precision. The hybrid code is
applied to two sample problems: the effect of finite-N gravitational
fluctuations on the orbits of the S-stars; and inspiral of an intermediate-mass
black hole into the galactic center.

12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: econ
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
2
The categories of this paper are: math
1
The categories of this paper are: cs
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The categories of this paper are: chao-dyn
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The categories of this paper are: hep-ex
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The categories of this paper are: nlin
30
The categories of this paper are: q-alg