期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 425, 期 3, 页码 2128-2143出版社
OXFORD UNIV PRESS
DOI: 10.1111/j.1365-2966.2012.21567.x
关键词
cosmology: theory; dark energy; large-scale structure of Universe
资金
- Simons Foundation [184549]
- Kavli Institute for Cosmological Physics at the University of Chicago [NSF PHY-0114422, NSF PHY-0551142]
- Kavli Foundation
- Royal Astronomical Society
- Durham University
- STFC [ST/H002774/1]
- ERC
- Leverhulme Trust
- STFC
- Large Facilities Capital Fund of BIS
- STFC [ST/H002774/1] Funding Source: UKRI
- Division Of Physics
- Direct For Mathematical & Physical Scien [1125897] Funding Source: National Science Foundation
- Science and Technology Facilities Council [ST/H002774/1] Funding Source: researchfish
- UK Space Agency [ST/J001848/1, ST/J004995/1, ST/I002960/1] Funding Source: researchfish
We use large-volume N-body simulations to predict the clustering of dark matter in redshift space in f(R) modified gravity cosmologies. This is the first time that the non-linear matter and velocity fields have been resolved to such a high level of accuracy over a broad range of scales in this class of models. We find significant deviations from the clustering signal in standard gravity, with an enhanced boost in power on large scales and stronger damping on small scales in the f(R) models compared to general relativity (GR) at redshifts z < 1. We measure the velocity divergence (P??) and matter (Pdd) power spectra and find a large deviation in the ratios P??/Pdd and Pd?/Pdd between the f(R) models and GR for 0.03 < k/(h?Mpc-1) < 0.5. In linear theory, these ratios equal the growth rate of structure on large scales. Our results show that the simulated ratios agree with the growth rate for each cosmology (which is scale-dependent in the case of modified gravity) only for extremely large scales, k < 0.06?h?Mpc-1 at z = 0. The velocity power spectrum is substantially different in the f(R) models compared to GR, suggesting that this observable is a sensitive probe of modified gravity. We demonstrate how to extract the matter and velocity power spectra from the 2D redshift-space power spectrum, P(k, mu), and can recover the non-linear matter power spectrum to within a few per cent for k < 0.1?h?Mpc-1. However, the model fails to describe the shape of the 2D power spectrum, demonstrating that an improved model is necessary in order to reconstruct the velocity power spectrum accurately. The same model can match the monopole moment to within 3 per cent for GR and 10 per cent for the f(R) cosmology at k < 0.2?h?Mpc-1 at z = 1. Our results suggest that the extraction of the velocity power spectrum from future galaxy surveys is a promising method to constrain deviations from GR.
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