Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Merging history as a function of halo environment   According to the hierarchical scenario, galaxies form via merging and
accretion of small objects. Using N-body simulations, we study the frequency of
merging events in the history of the halos. We find that at z<~2 the merging
rate of the overall halo population can be described by a simple power law
(1+z)^3. The main emphasis of the paper is on the effects of environment of
halos at the present epoch (z=0). We find that the halos located inside
clusters have formed earlier (dz \approx 1) than isolated halos of the same
mass. At low redshifts (z<1), the merger rate of cluster halos is 3 times lower
than that of isolated halos and 2 times lower than merger rate of halos that
end up in groups by z=0. At higher redshifts (z~1-4), progenitors of cluster
and group halos have 3--5 times higher merger rates than isolated halos. We
briefly discuss implications of our results for galaxy evolution in different
environments.

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The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn