Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Cosmological Mass Function with Broken Hierarchy   We construct an analytic formalism for the mass function of cold dark matter
halos, assuming that there is a break in the hierarchical merging process.
According to this {\it broken-hierarchy} scenario, due to the inherent nature
of the gravitational tidal field the formation of massive pancakes precedes
that of dark halos of low-mass. In the framework of the Zel'dovich
approximation which generically predicts the presence of pancakes, we first
derive analytically the conditional probability that a low-mass halo observed
at present epoch was embedded in an isolated pancake at some earlier epoch.
Then, we follow the standard Press-Schechter approach to count analytically the
number density of low-mass halos that formed through anti-hierarchical
fragmentation of the massive pancakes. Our mass function is well approximated
by a power-law dN/dM = M^{-l} in the mass range 10^{6}M_{sun}/h < M <
10^{10}M_{sun}/h with the slope l=1.86 shallower than that of the currently
popular Sheth-Tormen mass function l = 2.1. It is expected that our mass
function will provide a useful analytic tool for investigating the effect of
broken hierarchy on the structure formation.

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The categories of this paper are: eess
32
The categories of this paper are: atom-ph
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
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The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
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The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
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The categories of this paper are: cond-mat
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The categories of this paper are: chem-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: q-fin