Baryon oscillations in galaxy and matter power-spectrum covariance matrices

Abstract

We investigate large-amplitude baryon acoustic oscillations (BAO's) in off-diagonal entries of cosmological power-spectrum covariance matrices. These covariance-matrix BAO's describe the increased attenuation of power-spectrum BAO's caused by upward fluctuations in large-scale power. We derive an analytic approximation to covariance-matrix entries in the BAO regime, and check the analytical predictions using N-body simulations. These BAO's look much stronger than the BAO's in the power spectrum, but seem detectable only at about a one-sigma level in gigaparsec-scale galaxy surveys. In estimating cosmological parameters using matter or galaxy power spectra, including the covariance-matrix BAO's can have a several-percent effect on error-bar widths for some parameters directly related to the BAO's, such as the baryon fraction. Also, we find that including the numerous galaxies in small haloes in a survey can reduce error bars in these cosmological parameters more than the simple reduction in shot noise might suggest.

11 pages, 11 figures, accepted to MNRAS. Minor changes to match accepted version. CosmoPy (Cosmological Python) code available at http://ifa.hawaii.edu/cosmopy/

References in corpus (9)

• Measuring the Baryon Acoustic Oscillation scale using the SDSS and 2dFGRS
• Transients from Initial Conditions in Cosmological Simulations
• On the Robustness of the Acoustic Scale in the Low-Redshift Clustering of Matter
• The shape of the SDSS DR5 galaxy power spectrum
• The Scale Dependence of Halo and Galaxy Bias: Effects in Real Space
• The detectability of baryonic acoustic oscillations in future galaxy surveys
• Dark matter clustering: a simple renormalization group approach
• Simulations of Baryon Oscillations
• Information content in the halo-model dark-matter power spectrum

Cited by in corpus (7)

• Simulations of Baryon Acoustic Oscillations II: Covariance matrix of the matter power spectrum
• An analytic model for the bispectrum of galaxies in redshift space
• Forecasting the Cosmological Constraints with Anisotropic Baryon Acoustic Oscillations from Multipole Expansion
• Quantifying distortions of the Lagrangian dark-matter mesh in cosmology
• Simulations of Baryon Acoustic Oscillations I: Growth of Large-Scale Density Fluctuations
• Large-scale structure perturbation theory without losing stream crossing
• Removable Matter-Power-Spectrum Covariance from Bias Fluctuations