Cosmological model with time varying deceleration parameter in F(R, G) gravity

Lohakare, Santosh V; Tripathy, S. K.; Mishra, B.

doi:10.1088/1402-4896/ac40d6

Cited by 13 publications

(5 citation statements)

References 65 publications

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“…Moreover, with the suitable choice for F leading to F (R, G) = R, one recovers Einstein's GR as well. Thus, one can see that this modified gravity theory being the generalized version of both F (R) and F (G) gravity theories can offer some appealing consequences and very soon of its introduction, F (R, G) gravity theory received significant attention in the community [573,608,623,625,[630][631][632][633][634][635][636][637][638][639][640][641][642][643][644][645].…”

Section: G F (R G) Gravitymentioning

confidence: 99%

Finite-time cosmological singularities and the possible fate of the Universe

de Haro,

Nojiri,

Odintsov

et al. 2023

Physics Reports

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Section: G F (R G) Gravitymentioning

confidence: 99%

Finite-time cosmological singularities and the possible fate of the Universe

de Haro,

Nojiri,

Odintsov

et al. 2023

Physics Reports

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“…Subsequently, Singh et al [46] explored the bulk viscous FRW cosmos and demonstrated that the universe's current acceleration is due to the contribution of viscosity. There have been several excellent studies in the literature for confining the various homogeneous and isotropic universe features in various gravitational theories [47][48][49][50][51]. In the present manuscript, we have explored an accelerating cosmic model of a hybrid universe in f (R, T ) theory.…”

Section: Introductionmentioning

confidence: 99%

Hybrid scale factor and late time acceleration of universe in f(R, T) gravity

Jayas,

Bhardwaj

2024

Indian J Phys

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In this paper, we have discussed a model of transitioning universe in f (R, T ) gravity, depicting late-time accelerated expansion. We developed and presented exact solutions of field equations of the proposed model. The scale factor of hybrid law in the forma(t) = t α e βt , with constants α and β, is assumed to propose the explicit solution of the field equations developed for a homogeneous and isotropic universe inf (R, T ) gravity. The model parameters have been extracted using the latest observational finding of the OHD data set. The best-fit values are estimated using the MCMC method. Features like the deceleration parameter and jerk parameter are explored. Further Om and statefinder diagnosis of the assumed model are also discussed for geometrical comparison with the standard ΛCDM model. We have also discussed the stability of the proposed solution through perturbation analysis.

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“…Furthermore, the cosmographic parameters are investigated. In the case of an accelerated expanding Universe, the deceleration parameter q should take negative values and tend to the value q = −1 [39,40]. Partially, based on cosmographic parameters, the values of the statefinders are calculated [41,42].…”

Section: Introductionmentioning

confidence: 99%

The Early and Late Universe in the Modified Einstein-Maxwell-Gauss-Bonnet Model

Tsyba,

Rakhatov,

Razina

2024

Preprint

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This work investigates the Einstein-Gauss-Bonnet model with scalar and electromagnetic fields. The created model was reconstructed using a hybrid scale factor. The initial viability analysis of the model confirmed the compliance of the solutions with modern cosmological data. The equation of state parameter $\omega$, corresponds to the case of an accelerated expanding universe. In addition, an alternative approach utilizing $Om(z)$ diagnostics has been implemented. The values of the scalar field and its potential obtained during the solution correspond to the cases of "slow-roll" and chaotic inflation. The values of the slow-roll parameters, based on the coupling function $\xi(\phi)$ are obtained. Parameters correspond to the condition of the beginning of inflation. Based on the slow-roll parameters, the values of the spectral indices $n_S$, $n_T$, and the tensor-to-scalar ratio $r$ are obtained. The propagation speed of the acoustic ($c_A$) and tensor ($c_T$) perturbations have been determined. Subsequently, an examination of the post-inflationary phase in the universe's evolution was conducted. This analysis was predicated on the utilization of energy conditions. Furthermore, an extensive evaluation involving cosmographic parameters and statefinders diagnostics was executed. The application of the described methods has shown that the model is stable, viable, and can be used to study the early and late stages of the universe's evolution.

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Cosmological model with time varying deceleration parameter in F(R, G) gravity

Cited by 13 publications

References 65 publications

Finite-time cosmological singularities and the possible fate of the Universe

Finite-time cosmological singularities and the possible fate of the Universe

Hybrid scale factor and late time acceleration of universe in f(R, T) gravity

The Early and Late Universe in the Modified Einstein-Maxwell-Gauss-Bonnet Model

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