Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Dynamical Evolution of Galaxy Groups. A comparison of two approaches   In this paper we test the performance of explicit simulations of groups of
galaxies, (i.e. simulations in which each galaxy is treated as a mass point and
the physics of the interactions is modelled by specific analand the physics of
the interactions is modelled by specific analytical prescriptions for merging
conditions), by comparing them with fully self-consistent simulations starting
from identical initial conditions. The quality of the explicit simulations is
very unequal. For somThe quality of the explicit simulations is very unequal.
For some prescriptions the results are complete disagreement with the
self-consistent simulations. The inclusion of other dynamical effects like
dynamical friction gives, in some cases, better agreeement.like dynamical
friction gives, in some cases, better agreeement. We also propose a new merging
criterion, which, combined with dynamical friction, gives much better agreement
with self-consistent simulations in a variety of initial conditions, but even
this criterion has a limited ranof initial conditions, but even this criterion
has a limited range of applicability.

8
The categories of this paper are: hep-ex
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
16
The categories of this paper are: stat
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
25
The categories of this paper are: patt-sol