High-Precision Large-Scale Structure: The Baryon Acoustic Oscillations and Passive Flow

Abstract

We present a precision study of large-scale structure from large galaxy redshift surveys. We focus on two main subjects of large-scale structure: precisioncosmology with baryon acoustic oscillations from large galaxy surveys and the evolution of galaxy clustering for passively flowing galaxies.The baryon acoustic oscillations in galaxy redshift surveys can serve as an efficient standard ruler to measure the cosmological distance scale, i.e., theangular diameter distances and Hubble parameters, as a function of redshift, and therefore dark energy parameters. We use a Fisher matrix formalism to show that such a standard ruler tests can constrain the angular diameter distances and Hubble parameters to a precision of a few percent, thereby providing robust measurements of present-day dark energy density and its time-dependence.We use N-body simulations to investigate possible systematic errors in the recovery of the cosmological distance scale from galaxy redshift surveys. We show that the baryon signature on linear and quasi-linear scales is robust against nonlinear growth, redshift distortions, and halo (or galaxy) bias, albeit partial obscuration of the signature occurs due to nonlinear growth and redshift distortions.We present the improved Fisher matrix formalism which incorporates the Lagrangian displacement field to describe the nonlinear effects on baryon signature as a function of time and scale. We present a physically motivated, reduced 2-dimensional fitting formula for the full Fisher matrix formalism. We show that distance precision from the revised formalism is in excellent agreement with distance precision from N-body simulations.Finally, we present a numerical study of the evolution of galaxy clustering when galaxies flow passively from high redshift to low redshift, that is, without merging or new formations. We show that passive flow evolution induces interesting characteristics in the galaxy distribution at low redshift: we find an asymptotic convergence in galaxy clustering and halo occupation distribution regardless of the initial distribution of galaxies.