Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Trends in Large Scale Structure Observations and the Likelihood of Early
  Reionization   With the imminent promise of constraints on the epoch of reionization from
observations of microwave background anisotropies, the question of whether or
not the standard Cold Dark Matter (CDM) model permits early reionization has
been subjected to detailed investigation by various authors, with the
conclusion that reionization may occur at quite high redshift. However, it is
widely accepted that this model is excluded, as when normalised to the COBE
observations it possesses excessive galaxy clustering on scales below tens of
megaparsecs. We examine the trends of observations, first in a fairly model
independent way, and second by considering variants on the standard CDM model
introduced to resolve the observational conflicts. We conclude that the epoch
of reionization favoured by the observational data is typically considerably
later than the standard CDM model suggests, and amongst models which may fit
the observational data only the introduction of a cosmological constant leads
to a reionization redshift close to that of standard CDM.

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The categories of this paper are: physics
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
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The categories of this paper are: nlin
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The categories of this paper are: nucl-ex