On the Robustness of the Acoustic Scale in the Low-Redshift Clustering of Matter

Abstract

We discuss the effects of non-linear structure formation on the signature of acoustic oscillations in the late-time galaxy distribution. We argue that the dominant non-linear effect is the differential motion of pairs of tracers separated by 150 Mpc. These motions are driven by bulk flows and cluster formation and are much smaller than the acoustic scale itself. We present a model for the non-linear evolution based on the distribution of pairwise Lagrangian displacements that provides a quantitative model for the degradation of the acoustic signature, even for biased tracers in redshift space. The Lagrangian displacement distribution can be calibrated with a significantly smaller set of simulations than would be needed to construct a precise power spectrum. By connecting the acoustic signature in the Fourier basis with that in the configuration basis, we show that the acoustic signature is more robust than the usual Fourier-space intuition would suggest because the beat frequency between the peaks and troughs of the acoustic oscillations is a very small wavenumber that is well inside the linear regime. We argue that any possible shift of the acoustic scale is related to infall on 150 Mpc scale, which is O(0.5%) fractionally at first-order even at z=0. For the matter, there is a first-order cancellation such that the mean shift is O(10^{-4}). However, galaxy bias can circumvent this cancellation and produce a sub-percent systematic bias.

27 pages, LaTeX. Submitted to the Astrophysical Journal

References in corpus (1)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology

Cited by in corpus (22)

• Measuring the Baryon Acoustic Oscillation scale using the SDSS and 2dFGRS
• Improving Cosmological Distance Measurements by Reconstruction of the Baryon Acoustic Peak
• Resumming Cosmological Perturbations via the Lagrangian Picture: One-loop Results in Real Space and in Redshift Space
• Clustering of dark matter tracers: generalizing bias for the coming era of precision LSS
• Large-Scale Anisotropic Correlation Function of SDSS Luminous Red Galaxies
• The detectability of baryonic acoustic oscillations in future galaxy surveys
• `Eppur Si Muove': On The Motion of the Acoustic Peak in the Correlation Function
• Non-linear structure formation and the acoustic scale
• Reconstructing Baryon Oscillations: A Lagrangian Theory Perspective
• Calibrating the Baryon Oscillation Ruler for Matter and Halos
• Baryon acoustic signature in the clustering of density maxima
• Perturbation Theory Reloaded II: Non-linear Bias, Baryon Acoustic Oscillations and Millennium Simulation In Real Space
• Distance, Growth Factor, and Dark Energy Constraints from Photometric Baryon Acoustic Oscillation and Weak Lensing Measurements
• The Acoustic Peak in the Lyman Alpha Forest
• Complete Treatment of Galaxy Two-Point Statistics: Gravitational Lensing Effects and Redshift-Space Distortions
• What is the best way to measure baryonic acoustic oscillations?
• Luminous Red Galaxy Halo Density Field Reconstruction and Application to Large Scale Structure Measurements
• Luminous Red Galaxy Clustering at z~0.7 - First Results using AAOmega
• Forecasting the Dark Energy Measurement with Baryon Acoustic Oscillations: Prospects for the LAMOST surveys
• Constraining dark energy via baryon acoustic oscillations in the (an)isotropic light-cone power spectrum
• Baryon oscillations in galaxy and matter power-spectrum covariance matrices
• Confronting the damping of the baryon acoustic oscillations with observation