Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Delayed Recombination and Standard Rulers   Measurements of Baryonic Acoustic Oscillations in galaxy surveys have been
recognized as a powerful tool for constraining dark energy. However, this
method relies on the knowledge of the size of the acoustic horizon at
recombination derived from Cosmic Microwave Background Anisotropy measurements.
This estimate is typically derived assuming a standard recombination scheme;
additional radiation sources can delay recombination altering the cosmic
ionization history and the cosmological inferences drawn from CMB and BAO data.
In this paper we quantify the effect of delayed recombination on the
determination of dark energy parameters from future BAO surveys such as BOSS
and WFMOS. We find the impact to be small but still not negligible. In
particular, if recombination is non-standard (to a level still allowed by CMB
data), but this is ignored, future surveys may incorrectly suggest the presence
of a redshift dependent dark energy component. On the other hand, in the case
of delayed recombination, adding to the analysis one extra parameter describing
deviations from standard recombination, does not significantly degrade the
error-bars on dark energy parameters and yields unbiased estimates.

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The categories of this paper are: acc-phys
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The categories of this paper are: econ
12
The categories of this paper are: nucl-th
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
33
The categories of this paper are: plasm-ph
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The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
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The categories of this paper are: adap-org
4
The categories of this paper are: cond-mat
35
The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: bayes-an
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-ex
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The categories of this paper are: physics