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arXiv · 2302.07022

Late-time cosmology in a model of modified gravity with an exponential function of the curvature

A. Oliveros·Mario A. Acero
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Abstract

In this work, we analyse the late-time evolution of the universe for a particular $f(R)$ gravity model built from an exponential function of the scalar curvature. Following the literature, we write the field equations in terms of a suited statefinder function ($y_H(z)$) and considering well motivated physical initial conditions, the resulting equations are solved numerically. Also, the cosmological parameters $w_{\rm{DE}}$, $w_{\rm{eff}}$, $\Omega_{\rm{DE}}$ and $H(z)$ and the statefinder quantities $q$, $j$, $s$ and $Om(z)$ are explicitly expressed in terms of $y_H(z)$ and its derivatives. Furthermore, setting an appropriate set of values for the model parameters, the cosmological parameters as well as the statefinder quantities are plotted, and their present values (at $z=0$), are shown to be compatible with Planck 2018 observations and the $\Lambda$CDM-model values. Considering updated measurements from the dynamics of the expansion of the universe, $H(z)$, we perform an statistical analysis to constrain the free parameters of the model, finding a particular set of values that fit the data well and predict acceptable values for the cosmological and statefinder parameters at present time. Therefore, the $f(R)$ gravity model is found to be consistent with the considered observational data, and a viable alternative to explain the late-time acceleration of the universe.

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BibTeXRIS

A. Oliveros, Mario A. Acero. 2023-02-14. Late-time cosmology in a model of modified gravity with an exponential function of the curvature. https://arxiv.org/abs/2302.07022

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