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arXiv · 1807.00798

Big-bang nucleosynthesis and cosmic microwave background constraints on non-minimally coupled theories of gravity

R. P. L. Azevedo·P. P. Avelino
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Abstract

In this paper we show that the baryon-to-photon ratio $η$ is in general not conserved before decoupling in non-minimally coupled theories of gravity. We use big-bang nucleosynthesis and cosmic microwave background limits on the baryon-to-photon ratio $η$ to derive new constraints on modified gravity theories with a universal non-minimal coupling between matter and curvature, showing that they rule out a specific class of models previously considered in the literature as a substitute for the dark matter. We also compare these new constraints with the ones obtained from the COBE-FIRAS limits on CMB spectral distortions, highlighting the complementarity between them.

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R. P. L. Azevedo, P. P. Avelino. 2018-07-02. Big-bang nucleosynthesis and cosmic microwave background constraints on non-minimally coupled theories of gravity. https://doi.org/10.1103/physrevd.98.064045

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