Year: 2019
Type: preprint
Abstract: A novel function for modified gravity is proposed, $f(R, T)=R+λR^2+2β\ln(T)$, with constants $λ$ and $β$, scalar curvature $R$, and the trace of stress energy tensor $T$, satisfying $T=ρ-3p>0$. Subsequently, two equations of state (EoS) parameters, namely $ω$ and a parametric form of the Hubble parameter $H$, are employed in order to study the accelerated expansion and initial cosmological bounce of the corresponding universe. Hubble telescope experimental data for redshift $z$ within the range $0.07\leq z \leq 2.34$ are used to compare the theoretical and observational values of the Hubble parameter. Moreover, it is observed that all the energy conditions are fulfilled within a neighborhood of the bouncing point $t=0$, what shows that the necessary condition for violation of the null energy condition, within a neighborhood of the bouncing point in general relativity, could be avoided by modifying the theory in a reasonable way. Furthermore, a large amount of negative pressure is found, which helps to understand the late time accelerated expansion phase of the universe.
Source: arXiv (Cornell University)
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G4790078167, G657301660
OpenAlex ID: W2959315546