We study a new procedure to measure the sound horizon scale via Baryonic Acoustic Oscillations (BAO). Instead of fitting the measured power spectrum (PS) to a theoretical model containing the cosmological informations and all the nonlinear effects, we define a procedure to project out (or to "extract") the oscillating component from a given nonlinear PS. We show that the BAO scale extracted in this way is extremely robust and, moreover, can be reproduced by simple theoretical models at any redshift. By using N-body simulations, we discuss the effect of the nonlinear evolution of the matter field, of redshift space distortions and of scale-dependent halo bias, showing that all these effects can be reproduced with sub-percent accuracy. We give a one-parameter theoretical model based on a simple (IR) modification of 1-loop perturbation theory, which reproduces the BAO scale from measurements of halo clustering in redshift space at better than 0.1% level and does not need any external UV input, such as coefficients measured from N-body simulations.
Bibliographical noteFunding Information:
E. Noda and M. Pietroni acknowledge support from the European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreements Invisible-sPlus RISE No. 690575, Elusives ITN No. 674896 and Invisibles ITN No. 289442. The work of M. Peloso was supported in part by DOE grant de-sc0011842 at the University of Minnesota. T. Nishimichi acknowledges financial support from Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 17K14273 and Japan Science and Technology Agency (JST) CREST Grant Number JPMJCR1414. Numerical calculations for the present work have been carried out on Cray XC30 at Center for Computational Astrophysics, CfCA, of National Astronomical Observatory of Japan.
© 2018 IOP Publishing Ltd and Sissa Medialab.
- baryon acoustic oscillations
- cosmological parameters from LSS
- cosmological perturbation theory