Removing BAO-peak Shifts with Local Density Transforms

Abstract

Large-scale bulk flows in the Universe distort the initial density field, broadening the baryon-acoustic-oscillation (BAO) feature that was imprinted when baryons were strongly coupled to photons. Additionally, there is a small shift inward in the peak of the conventional overdensity correlation function, a mass-weighted statistic. This shift occurs when high density peaks move toward each other. We explore whether this shift can be removed by applying to the density field a transform (such as a logarithm) that gives fairer statistical weight to fluctuations in underdense regions. Using configuration-space perturbation theory in the Zel'dovich approximation, we find that the log-density correlation function shows a much smaller inward shift in the position of the BAO peak at low redshift than is seen in the overdensity correlation function. We also show that if the initial, Lagrangian density of matter parcels could be estimated at their Eulerian positions, giving a displaced-initial-density field, its peak shift would be even smaller. In fact, a transformed field that accentuates underdensities, such as the reciprocal of the density, pushes the peak the other way, outward. In our model, these shifts in the peak position can be attributed to shift terms, involving the derivative of the linear correlation function, that entirely vanish in this displaced-initial-density field.

5 pages, 3 figures, Accepted by ApjL

References in corpus (24)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Efficient Computation of CMB anisotropies in closed FRW models
• Detection of the Baryon Acoustic Peak in the Large-Scale Correlation Function of SDSS Luminous Red Galaxies
• The 2dF Galaxy Redshift Survey: Power-spectrum analysis of the final dataset and cosmological implications
• The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in the Data Release 9 Spectroscopic Galaxy Sample
• A 2% Distance to z=0.35 by Reconstructing Baryon Acoustic Oscillations - I : Methods and Application to the Sloan Digital Sky Survey
• 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
• Nonlinear Evolution of Baryon Acoustic Oscillations
• Rejuvenating the matter power spectrum: restoring information with a logarithmic density mapping
• `Eppur Si Muove': On The Motion of the Acoustic Peak in the Correlation Function
• Non-linear structure formation and the acoustic scale
• Non-linear Evolution of Baryon Acoustic Oscillations from Improved Perturbation Theory in Real and Redshift Spaces
• The Shift of the Baryon Acoustic Oscillation Scale: A Simple Physical Picture
• Calibrating the Baryon Oscillation Ruler for Matter and Halos
• Galaxy Bias and its Effects on the Baryon Acoustic Oscillations Measurements
• Reconstruction of primordial density fields
• On the incompleteness of the moment and correlation function hierarchy as probes of the lognormal field
• On the inadequacy of N-point correlation functions to describe nonlinear cosmological fields: explicit examples and connection to simulations
• Linearisation with Cosmological Perturbation Theory
• Observational biases in Lagrangian reconstructions of cosmic velocity fields
• Rejuvenating the Matter Power Spectrum III: The Cosmology Sensitivity of Gaussianized Power Spectra
• Nonlinear Behavior of Baryon Acoustic Oscillations from the Zel'dovich Approximation Using a Non-Fourier Perturbation Approach
• Straightening the Density-Displacement Relation with a Logarithmic Transform

Cited by in corpus (18)

• Cosmology with the Large Synoptic Survey Telescope: an Overview
• The Clustering of Galaxies in the SDSS-III DR10 Baryon Oscillation Spectroscopic Survey: No Detectable Colour Dependence of Distance Scale or Growth Rate Measurements
• The Accuracy of Weak Lensing Simulations
• Ringing the initial Universe: the response of overdensity and transformed-density power spectra to initial spikes
• Evidence for an environment-dependent shift in the baryon acoustic oscillation peak
• BAO reconstruction: a swift numerical action method for massive spectroscopic surveys
• Density-dependent clustering: I. Pulling back the curtains on motions of the BAO peak
• Improving baryon acoustic oscillation measurement with the combination of cosmic voids and galaxies
• The redshift-space galaxy two-point correlation function and baryon acoustic oscillations
• Simulating the Anisotropic Clustering of Luminous Red Galaxies with Subhalos: A Direct Confrontation with Observation and Cosmological Implications
• Measuring the BAO peak position with different galaxy selections
• Weighted density fields as improved probes of modified gravity models
• The Effective Field Theory and Perturbative Analysis for Log-Density Fields
• Perturbative Gaussianizing transforms for cosmological fields
• Cosmic void exclusion models and their impact on the distance scale measurements from large scale structure
• The environmental dependence of the baryon acoustic peak in the Baryon Oscillation Spectroscopic Survey CMASS sample
• Mass-Dependent Baryon Acoustic Oscillation Signal and Halo Bias
• Baryon Acoustic Oscillations analyses with Density-Split Statistics