Characteristic Scales of Baryon Acoustic Oscillations from Perturbation Theory: Non-linearity and Redshift-Space Distortion Effects

• Published in: arXiv.org
• Main Authors: Nishimichi, Takahiro, Ohmuro, Hiroshi, Nakamichi, Masashi, Taruya, Atsushi, Yahata, Kazuhiro, Shirata, Akihito, Saito, Shun, Nomura, Hidenori, Yamamoto, Kazuhiro, Suto, Yasushi
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 20.08.2007
• Subjects: Acoustics; Baryons; Data analysis; Decoupling; Distortion; Galaxies; Galaxy distribution; Linearity; Nonlinearity; Perturbation theory; Physics - Astrophysics of Galaxies; Physics - Cosmology and Nongalactic Astrophysics; Physics - Earth and Planetary Astrophysics; Physics - High Energy Astrophysical Phenomena; Physics - Instrumentation and Methods for Astrophysics; Physics - Solar and Stellar Astrophysics; Predictions; Red shift; Universe
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.0705.1589

An acoustic oscillation of the primeval photon-baryon fluid around the decoupling time imprints a characteristic scale in the galaxy distribution today, known as the baryon acoustic oscillation (BAO) scale. Several on-going and/or future galaxy surveys aim at detecting and precisely determining the BAO scale so as to trace the expansion history of the universe. We consider nonlinear and redshift-space distortion effects on the shifts of the BAO scale in \(k\)-space using perturbation theory. The resulting shifts are indeed sensitive to different choices of the definition of the BAO scale, which needs to be kept in mind in the data analysis. We present a toy model to explain the physical behavior of the shifts. We find that the BAO scale defined as in Percival et al. (2007) indeed shows very small shifts (\(\lesssim\) 1%) relative to the prediction in {\it linear theory} in real space. The shifts can be predicted accurately for scales where the perturbation theory is reliable.