Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The flat-sky approximation to galaxy number counts - redshift space
  correlation function   We study the flat-sky approximation for galaxy number counts including
relativistic effects, and assess its performance and accuracy with respect to
the full-sky result. We find an agreement of up to 5% for the local and lensing
contributions to the 2-point correlation function and its multipoles at $z >
0.5$, and up to 1% for the multipoles alone at $z > 1$ and separations
$\lesssim 250$ Mpc/$h$, with a speed-up of over a factor of 1000. Using a
semi-analytic method, which has been implemented in a new version of the code
COFFE, along with the Limber approximation for the integrated contributions, we
further increase the performance, allowing the computation of the flat-sky
multipoles to be done over 10000 times faster than in the full-sky calculation,
which could be used to greatly speed-up Markov chain Monte Carlo sampling for
cosmological parameter estimation.

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The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph