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arXiv · 1306.6646

Large-scale 3D galaxy correlation function and non-Gaussianity

Alvise Raccanelli·Daniele Bertacca·Olivier Dore·Roy Maartens
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Abstract

We investigate the properties of the 2-point galaxy correlation function at very large scales, including all geometric and local relativistic effects -- wide-angle effects, redshift space distortions, Doppler terms and Sachs-Wolfe type terms in the gravitational potentials. The general three-dimensional correlation function has a nonzero dipole and octupole, in addition to the even multipoles of the flat-sky limit. We study how corrections due to primordial non-Gaussianity and General Relativity affect the multipolar expansion, and we show that they are of similar magnitude (when f_NL is small), so that a relativistic approach is needed. Furthermore, we look at how large-scale corrections depend on the model for the growth rate in the context of modified gravity, and we discuss how a modified growth can affect the non-Gaussian signal in the multipoles.

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Alvise Raccanelli, Daniele Bertacca, Olivier Dore, Roy Maartens. 2014-09-04. Large-scale 3D galaxy correlation function and non-Gaussianity. https://doi.org/10.1088/1475-7516%2F2014%2F08%2F022

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