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arXiv · 2408.01410

Evolution of an effective Hubble constant in $f(R)$ modified gravity

Tiziano Schiavone·Giovanni Montani
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Abstract

We investigate the Hubble constant tension within $f(R)$ modified gravity in the Jordan frame, focusing on its application to the dynamics of an isotropic Universe. A scalar field, non-minimally coupled to the metric, provides an extra degree of freedom compared to General Relativity. We analyze the impact of such a scalar field on the cosmic expansion, leading to an effective Hubble constant $H_{0}^{\text{eff}}(z)$, dependent on redshift $z$. We show that our $f(R)$ model might mimic dark energy and provide an apparent variation of the Hubble constant. Our results align with recent cosmological data analysis in redshift bins, indicating a decreasing trend of the Hubble constant. The redshift dependence of $H_{0}^{\text{eff}}(z)$ might potentially reconcile measurements of the Hubble constant from probes at different redshifts.

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Tiziano Schiavone, Giovanni Montani. 2024-08-02. Evolution of an effective Hubble constant in $f(R)$ modified gravity. https://arxiv.org/abs/2408.01410

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