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arXiv · 1312.1291

Modeling the nonlinear clustering in modified gravity models I: A fitting formula for matter power spectrum of f(R) gravity

Gong-Bo Zhao
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Abstract

Based on a suite of N-body simulations of the Hu-Sawicki model of f(R) gravity with different sets of model and cosmological parameters, we develop a new fitting formula with a numeric code, MGHalofit, to calculate the nonlinear matter power spectrum P(k) for the Hu-Sawicki model. We compare the MGHalofit predictions at various redshifts (z<=1) to the f(R) simulations and find that the accuracy on P(k) is 6% at k<1 h/Mpc and 12% at 1<k<10 h/Mpc respectively. Based on a sensitivity study of an ongoing and a future spectroscopic survey, we estimate the detectability of a signal of modified gravity described by the Hu-Sawicki model using the power spectrum up to quasi-nonlinear scales. MGHalofit is publicly available at http://icosmology.info/website/MGHalofit.html.

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Gong-Bo Zhao. 2014-02-16. Modeling the nonlinear clustering in modified gravity models I: A fitting formula for matter power spectrum of f(R) gravity. https://doi.org/10.1088/0067-0049%2F211%2F2%2F23

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