Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Constrained Simulations of Dark Matter Halos   The formation and structure of dark matter halos is studied by constrained
simulations. A series of experiments of the formation of a 10^12 Msun/h halo is
designed to study the dependence of the density profile on its merging history.
We find that the halo growth consist of several quiescent phases intermitted by
violent events, with the density well approximated by the NFW profile during
the former phases. We find that (1) the NFW scale radius R_s stays constant
during the quiescent phase and grows abruptly during the violent one. In
contrast, the virial radius grows linearly during the quiescent and abruptly
during the violent phases. (2) The central density stays unchanged during the
quiescent phase while dropping abruptly during the violent phase, and it does
not reflect the formation time of the halo. (3) The clear separation of the
evolution of an individual halo into quiescent and violent phases implies that
its entire evolution cannot be fitted by simple scaling relations.

19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
11
The categories of this paper are: hep-lat
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
32
The categories of this paper are: atom-ph