Nonlinear evolution of the matter power spectrum in modified theories of gravity

Journal Article · Mon Jun 15 04:00:00 EDT 2009 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.79.123512· OSTI ID:21300943

Koyama, Kazuya ^[1]; Taruya, Atsushi ^[2]; Hiramatsu, Takashi ^[3]

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1. Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, Hampshire, PO1 2EG (United Kingdom)
2. Research Center for the Early Universe, School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)
3. Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan)

We present a formalism to calculate the nonlinear matter power spectrum in modified gravity models that explain the late-time acceleration of the Universe without dark energy. Any successful modified gravity models should contain a mechanism to recover general relativity (GR) on small scales in order to avoid the stringent constrains on deviations from GR at solar system scales. Based on our formalism, the quasi-nonlinear power spectrum in the Dvali-Gabadadze-Porratti braneworld models and f(R) gravity models are derived by taking into account the mechanism to recover GR properly. We also extrapolate our predictions to fully nonlinear scales using the parametrized post-Friedmann framework. In the Dvali-Gabadadze-Porratti and f(R) gravity models, the predicted nonlinear power spectrum is shown to reproduce N-body results. We find that the mechanism to recover GR suppresses the difference between the modified gravity models and dark energy models with the same expansion history, but the difference remains large at the weakly nonlinear regime in these models. Our formalism is applicable to a wide variety of modified gravity models and it is ready to use once consistent models for modified gravity are developed.

• OSTI ID: 21300943
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 12 Vol. 79; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
ACCELERATION
BRANES
EVOLUTION
EXPANSION
FORECASTING
GENERAL RELATIVITY THEORY
GRAVITATION
GRAVITATIONAL INTERACTIONS
M-THEORY
NONLINEAR PROBLEMS
NONLUMINOUS MATTER
SIMULATION
SOLAR SYSTEM
SPECTRA
UNIVERSE