Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Age of the Universe in the Cardassian Model   The age of the universe is obtained in a subset of Cardassian models by using
WMAP data. Cardassian expansion is a modification to the Friedmann equation
that allows the universe to be flat, matter dominated, and accelerating,
without a vacuum component. Since this model changes the evolution of the
universe, we should not a priori expect the Cardassian age to be the same as
the WMAP Friedmann derived result of 13.7 +/- 0.2 Gyrs. However, in the subset
of Cardassian models we consider, we discover that the age of the universe
varies from 13.4 - 13.8 Gyr over the range of parameter space we explore, a
result close to that of the standard Lambda Cold Dark Matter model. The Hubble
constant h, which may also vary in these models, likewise varies little from
the Friedmann result.

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The categories of this paper are: dg-ga
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The categories of this paper are: acc-phys
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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
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The categories of this paper are: stat
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The categories of this paper are: q-fin
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The categories of this paper are: alg-geom
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The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
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The categories of this paper are: q-bio
1
The categories of this paper are: cs
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The categories of this paper are: quant-ph