Reconstructing baryon oscillations

Abstract

The baryon acoustic oscillation (BAO) method for constraining the expansion history is adversely affected by nonlinear structure formation, which washes out the correlation function peak created at decoupling. To increase the constraining power of low $z$ baryon acoustic oscillation experiments, it has been proposed that one use the observed distribution of galaxies to ``reconstruct'' the acoustic peak. Recently Padmanabhan, White, and Cohn provided an analytic formalism for understanding how reconstruction works within the context of Lagrangian perturbation theory (LPT). We extend that formalism to include the case of biased tracers of the mass in real space and, because the quantitative validity of LPT is questionable, we investigate reconstruction in $N$-body simulations. We find that LPT does a good job of explaining the trends seen in simulations for both the mass and for biased tracers in real space and comment upon the implications this has for reconstruction.