Beating non-linearities: improving the Baryon Acoustic Oscillations with the linear point

Aug 5, 2015
10 pages
Published in:
  • Mon.Not.Roy.Astron.Soc. 455 (2016) 3, 2474-2483
  • Published: Jan 21, 2016
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Abstract: (Oxford University Press)
We propose a new way of looking at the Baryon Acoustic Oscillation in the large-scale-structure clustering correlation function. We identify a scale s_LP that has two fundamental features: its position is insensitive to non-linear gravity, redshift-space distortions and scale-dependent bias at the 0.5 per cent level; it is geometrical, i.e. independent of the power spectrum of the primordial density fluctuation parameters. These two properties together make s_LP, called the ‘linear point’, an excellent cosmological standard ruler. The linear point is also appealing because it is easily identified irrespectively of how non-linearities distort the correlation function. Finally, the correlation function amplitude at s_LP is similarly insensitive to non-linear corrections to within a few per cent. Hence, exploiting the particular baryon features in the correlation function, we propose three new estimators for growth measurements. A preliminary analysis of s_LP in current data is encouraging.
Note:
  • 10 pages, 9 figures. Added discussion on the correlation function inflection point. This version matches the published MNRAS paper
  • large-scale structure of Universe
  • power spectrum: primordial
  • gravitation: nonlinear
  • correction: nonlinear
  • density: fluctuation
  • density: primordial
  • correlation function
  • baryon: oscillation: acoustic
  • scale dependence
  • estimator