| Extracting Angular Diameter Distance and Expansion Rate of the Universe from Two-dimensional Galaxy Power Spectrum at High Redshifts: Baryon Acoustic Oscillation Fitting versus Full Modeling (2008) | |||||||||
Abstract | |||||||||
| We present a method for extracting the angular diameter distances, $D_A$, and the expansion rates, $H$, of the universe from the {\it two-dimensional} Baryon Acoustic Oscillations (BAO) in the galaxy power spectrum. Our method builds upon the existing algorithm called the "fit-and-extract" (FITEX) method, which allows one to extract only $D_A^2/H$ from a spherically averaged one-dimensional power spectrum. We develop the FITEX-2d method, an extension of the FITEX method, to include the two-dimensional information, which allows us to extract $D_A$ and $H$ simultaneously. We test the FITEX-2d method using the Millennium Simulation as well as simplified Monte Carlo simulations with a bigger volume. The BAOs, however, contain only a limited amount of information. We show that the full modeling, including the overall shape of the power spectrum, yields much better determinations of $D_A$ and $H$, hence the dark energy equation of state parameters such as $w_0$ and $w_a$, than the BAO-only analysis by more than a factor of two, provided that non-linear effects are under control.. Comment: 14 pages, 8 figures. (v2) Detailed study on the effects of marginalization over the amplitude, redshift space distortion, and the shape of the primordial power spectrum is added. The Fisher matrix code is publicly available at http://gyudon.as.utexas.edu/~komatsu/CRL/index.html The details of the code are presented in Appendix | |||||||||
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