Speaker
Description
In this work, we numerically study the cosmological evolution of a coupling model of non-minimal derivatives with a potential term in front of the Ricci scalar tensor. Specifically, this work is devoted to the examination of the late time cosmoogy of John and George's field model. Using the FLRW metric, we determined the equations of motion that derive from the scalar field model used. We then form a system of equations that we solve numerically using two types of potentials, known in the literature, such as the power law potential, the exponential potential. We used the cosmological evolution quantity such as the Hubble parameter, the statefinder quantity, the statefinder parameters as well as the dark energy parameters such as the state equation and the energy density of dark energy. The numerical behavior of the quantities and parameters of the cosmological evolution obtained with the model used leads to a phenomenology compatible with the latest Planck data and reproducing the cold dark matter model with cosmological constant $\Lambda$CDM.
The action that describes John-George's model presents itself as such
\begin{eqnarray}{\label{action1}}
S = \int \sqrt{-g}\left[ \frac{M_{p}^{2}}{2}\left( 1+\epsilon V(\sqrt{\kappa }\phi)\right) \frac{R}{2\kappa} -\frac{1}{2}(g^{\mu\nu}+\gamma \kappa G^{\mu\nu})\nabla_{\mu}\phi\nabla_{\nu}\phi +\mathcal{L}_{m}\right] d^{4}x\nonumber\\
\end{eqnarray}
with $\kappa = \frac{1}{M_{p}^{2}}$, $\gamma$ and $\epsilon$ are dimensionless parameters.
| Abstract Category | Astrophysics & Cosmology |
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