Analyzing the H0 tension in F(R) gravity models

Sergei D Odintsov,Diego Sáez-Chillón Gómez,German S Sharov

doi:10.1016/j.nuclphysb.2021.115377

Abstract

The Hubble constant tension problem is analyzed in the framework of a class of modified gravity, the so-called F(R) gravity. To do so, we explore two models: an exponential and a power-law F(R) gravities, which includes an early dark energy (EDE) term in the latter. These models can describe both an early time inflationary epoch and the late time accelerating expansion of the universe. We confront both models with recent observational data including the Pantheon Type Ia supernovae sample, the latest measurements of the Hubble parameter H(z) from differential ages of galaxies (cosmic chronometers) and separately from baryon acoustic oscillations. Standard rulers data set from the Cosmic Microwave Background radiation are also included in our analysis. The estimations of the Hubble constant appear to be essentially depending on the set of observational data and vary in the range from 68 to 70.3 km/(s⋅Mpc). The fits of the other free parameters of the models are also obtained, revealing interesting consequences.

Highlights

Among current problems in modern cosmology, the tension among estimations of the Hubble constant H0 is one of the most striking and irritating for researchers
Over the last years such discrepancies among H0 measurements have been revealed through two different methods: by the Planck collaboration after collecting and analyzing data from the cosmic microwave background radiation (CMB) over the last 7 years [1,2,3], which provides an estimation of H0 = 67.4 ± 0.5 km s−1Mpc−1 (Planck18), and on the other hand by the SH0ES group of Hubble Space Telescope (HST) [4,5] with the last estimate given by H0 = 74.03 ± 1.42 km s−1Mpc−1 (SH0ES19)
This problem may be dealt as the discrepancy between observations at early and late cosmological time of our Universe [6], since HST group works with late time data while Planck collaboration combines observations from redshifts in a wide range 0 < z < 1100 and uses the standard CDM model as fiducial model, but the issue may be approached through a theoretical way

Summary

Introduction

Among current problems in modern cosmology, the tension among estimations of the Hubble constant H0 is one of the most striking and irritating for researchers. This problem may be dealt as the discrepancy between observations at early and late cosmological time of our Universe [6], since HST group works with late time data while Planck collaboration combines observations from redshifts in a wide range 0 < z < 1100 and uses the standard CDM model as fiducial model, but the issue may be approached through a theoretical way. Some other researchers tried to explain the tension by assuming that Planck or HST measurements might suffer from systematic errors [16], but this analysis did not lead to convincing solutions of the problem

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