Thursday, January 17, 2013

1301.3673 (Geraint Pratten et al.)

BAOs and Non-linearities: 3D Spherical Analysis    [PDF]

Geraint Pratten, Dipak Munshi
The Baryon Acoustic Oscillations (BAO) are features in the matter power spectrum on scales of order 100-150 h^{-1} Mpc that promise to be a powerful tool to constrain and test cosmological models. The BAO have attracted such attention that future upcoming surveys have been designed with the BAO at the forefront of the primary science goals. Recent studies have advocated the use of a spherical-Fourier Bessel (SFB) expansion for future wide field surveys that cover both wide and deep regions of the sky necessitating the simultaneous treatment of the spherical sky geometry as well as the extended radial coverage. In this paper we present and extended analysis of the BAOs using the SFB formalism by taking into account the role of non-linearities in the oscillations observed in the galaxy power spectrum. The SFB power spectrum has both radial and tangential dependence and it has been shown that in the limit that we approach a deep survey the SFB power spectrum is purely radial and collapses to the Cartesian Fourier power spectrum. This radialisation of information is shown to hold even in the presence of redshift space distortions and 1-loop corrections to the galaxy power spectrum albeit with modified tangential and radial dependence. As per previous studies we find that the introduction of non-linearities leads to a damping of the oscillations in the matter power spectrum.
View original: http://arxiv.org/abs/1301.3673

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