The impact of systematic uncertainties in N-body simulations on the precision cosmology from galaxy clustering: a halo model approach
Abstract
Dark matter N-body simulations provide a powerful tool to model the clustering of galaxies and help interpret the results of galaxy redshift surveys. However, the galaxy properties predicted from N-body simulations are not necessarily representative of the observed galaxy populations; for example, theoretical uncertainties arise from the absence of baryons in N-body simulations. In this work, we assess how the uncertainties in N-body simulations impact the cosmological parameters inferred from galaxy redshift surveys. Applying the halo model framework, we find that the velocity bias of galaxies in modelling the redshift-space distortions is likely to be the predominant source of systematic bias. For a deep, wide survey like BigBOSS, current 10 per cent uncertainties in the velocity bias limit kmax to 0.14 h Mpc-1. In contrast, we find that the uncertainties related to the density profiles and the galaxy occupation statistics lead to relatively insignificant systematic biases. Therefore, the ability to calibrate the velocity bias accurately - from observations as well as simulations - will likely set the ultimate limit on the smallest length scale that can be used to infer cosmological information from galaxy clustering.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2013
- DOI:
- 10.1093/mnras/stt1200
- arXiv:
- arXiv:1303.0835
- Bibcode:
- 2013MNRAS.434.2556W
- Keywords:
-
- cosmological parameters;
- dark energy;
- dark matter;
- large-scale structure of Universe;
- Astrophysics - Cosmology and Extragalactic Astrophysics
- E-Print:
- 18 pages, 8 figures