Dynamical features of a quintom dark energy model with Galileon corrections

The paper extends basic Einstein--Hilbert action by adding an invariant constructed from a specific contraction between the Einstein tensor and the energy momentum tensor, encoding a non--minimal coupling between the space--time geometry and the matter fields. The fundamental Einstein--Hilbert action is extended by considering a generic function ${f}(R,G_{\mu \nu}T^{\mu \nu})$ which is further decomposed into its main constituents, a geometric component which depends on the scalar curvature, and a second element embedding the interplay between geometry and matter fields. Specific cosmological models are established at the level of background dynamics, based on particular couplings between the matter energy--momentum tensor and the Einstein tensor. After deducing the resulting field equations, the physical aspects for the cosmological model are investigated by employing a dynamical system analysis for various coupling functions. The investigation showed that the present model is compatible with different epochs in the evolution of our Universe, possible explaining various late time historical stages.

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“…For this project, we utilized Wolfram Mathematica for several analytical computations [82] -xAct [83].…”

Section: Acknowledgementsmentioning

confidence: 99%

Physical aspects of modified gravity theories

Marciu

Maria

2023

Chinese Phys. C

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“…All of these theories have been studied exhaustively in the last years [41][42][43][44][45][46][47][48][49], showing specific advantages over the ΛCDM scenario [50]. The dark energy phenomenon can be also triggered by a scalar field embedded into action [6,51], which can be minimally or non-minimally coupled [21] in the form of quintessence [52], phantom [53], or quintom scenarios [54][55][56][57][58][59][60]. In the modified gravity theories, a particular invariant based on the contraction between the matter energy-momentum tensor and the Ricci tensor R µν T µν has been considered [43,61], taking into account a possible interplay between the space-time geometry and the fundamental characteristics of the matter component, embedded into the specific form of the energy-momentum tensor.…”

Section: Introductionmentioning

confidence: 99%

Physical aspects of ${f}(R,G_{μν}T^{μν})$ modified gravity theories

Marciu¹,

Maria²

2023

Preprint

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“…Because of the importancy of the quintom model, there are a plethora of studies in the literature, we refer the reader in [22][23][24][25][26][27][28] and references therein. There are various extensions and generalizations of the quintm model in modified theories of gravity, for instance in scalar-tensor theory [29,30], in Galilleon cosmology [31], in scalar-torsion theory [32], in Gauss-Bonnet theory [33].…”

Section: Introductionmentioning

confidence: 99%

Unified dark energy from Chiral-Quintom model with a mixed potential in Friedmann–Lemaître–Robertson–Walker cosmology

Paliathanasis

2023

Eur. Phys. J. C

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For a spatially Friedmann–Lemaître–Robertson–Walker cosmology, we propose a multi-scalar field gravitational model. Specifically, we consider a two-scalar field cosmological model in which the kinetic components of the scalar fields establish a two-dimensional sphere of Lorentzian signature. For our Chiral-Quintom model we choose a mixed potential term $$V\left( \phi ,\psi \right) =V_{0}e^{\lambda \phi }+U_{0}e^{\kappa \phi }\psi ^{\frac{1}{\sigma } }$$ V ϕ , ψ = V 0 e λ ϕ + U 0 e κ ϕ ψ 1 σ and we investigate the asymptotic limits of the cosmological parameters. This model for $$U_{0}=0$$ U 0 = 0 , provides a generalization of the hyperbolic inflation where the equation of the state parameter can cross the phantom divide line. When $$U_{0}\ne 0$$ U 0 ≠ 0 we observe that this cosmological model exhibits asymptotic solutions that encompass accelerated universes, big rip singularities, and dust-like solutions. Hence, this multi-scalar field model it can be regarded as as a dark energy unify model which describes a variety of asymptotic cosmological scenarios.

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Dynamical features of a quintom dark energy model with Galileon corrections

Cited by 10 publications

References 62 publications

Physical aspects of modified gravity theories

Physical aspects of modified gravity theories

Physical aspects of ${f}(R,G_{μν}T^{μν})$ modified gravity theories

Unified dark energy from Chiral-Quintom model with a mixed potential in Friedmann–Lemaître–Robertson–Walker cosmology

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