Quintom dark energy with nonminimal coupling

We study the phase space of the quintom cosmologies for a class of exponential potentials. We combine normal forms expansions and the center manifold theory in order to describe the dynamics near equilibrium sets. Furthermore, we construct the unstable and center manifold of the massless scalar field cosmology motivated by the numerical results given in Lazkoz and Leon (Phys Lett B 638:303. arXiv:astro-ph/0602590, 2006). We study the role of the curvature on the dynamics. Several monotonic functions are defined on relevant invariant sets for the quintom cosmology. Finally, conservation laws of the cosmological field equations and algebraic solutions are determined by using the symmetry analysis and the singularity analysis.

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“…(e) m = 0.3, n = 0.5, γ = 1. Some orbits in the phase plane of the system (57),(58),(59) for the five choices of the parameters and ε = +1.…”

mentioning

confidence: 99%

The past and future dynamics of quintom dark energy models

León¹,

Paliathanasis²,

Morales-Martínez³

2018

Eur. Phys. J. C

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“…Moreover, since R = −T + B, one can also recover the cases coming from the standard curvature framework. For instance, the quintom model non-minimally coupled with the scalar curvature R studied in [34], can be also recovered by setting…”

Section: Generalised Teleparallel Quintom Dark Energy With Non-mimentioning

confidence: 99%

“…In this section we shall analyse the behavior of the present generalised quintom model in the teleparallel gravity theory by adopting a numerical approach previously considered by Perivolaropoulos in scalar tensor theories [69,70], and recently applied to a quintom scenario [34]. The present numerical approach enables us to analyse the effects of the scalar torsion and boundary coupling in the evolution of the corresponding quintom fields.…”

Section: Numerical Features Of the Quintom Modelmentioning

confidence: 99%

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Generalised teleparallel quintom dark energy non-minimally coupled with the scalar torsion and a boundary term

Bahamonde

Marciu

Rudra³

2018

J. Cosmol. Astropart. Phys.

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Within this work, we propose a new generalised quintom dark energy model in the teleparallel alternative of general relativity theory, by considering a non-minimal coupling between the scalar fields of a quintom model with the scalar torsion component T and the boundary term B. In the teleparallel alternative of general relativity theory, the boundary term represents the divergence of the torsion vector, B = 2∇µT µ , and is related to the Ricci scalar R and the torsion scalar T , by the fundamental relation: R = −T + B. We have investigated the dynamical properties of the present quintom scenario in the teleparallel alternative of general relativity theory by performing a dynamical system analysis in the case of decomposable exponential potentials. The study analysed the structure of the phase space, revealing the fundamental dynamical effects of the scalar torsion and boundary couplings in the case of a more general quintom scenario. Additionally, a numerical approach to the model is presented to analyse the cosmological evolution of the system.

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“…: V,-vol crossing [45] of the cosmological constant boundary. In the recent years the quintom paradigm [31] has been continuously developed in various studies [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] which includes the additions of various non-minimal couplings in different scalar tensor theories [61][62][63][64][65][66][67]. In spite of the fact that the quintom paradigm implies the violation of the null energy condition, embedding a pathological phantom field in the corresponding action, it remains as an admissible modified gravity construction which can justify various astrophysical observations [31].…”

Section: Introductionmentioning

confidence: 99%

Dynamical description of a quintom cosmological model nonminimally coupled with gravity

Marciu

2020

Eur. Phys. J. C

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In this work we have studied a cosmological model based on a quintom dark energy model non-minimally coupled with gravity, endowed with a specific potential energy of the exponential squared type. For this specific type of potential energy and non-minimal coupling, the dynamical properties are analyzed and the corresponding cosmological effects are discussed. Considering the linear stability method, we have investigated the dynamical properties of the phase space structure, determining the physically acceptable solutions. The analysis showed that in this model we can have various cosmological epochs, corresponding to radiation, matter domination, and de Sitter eras. Each solution is investigated from a physical and cosmological point of view, obtaining possible constraints of the model’s parameters. In principle the present cosmological setup represent a possible viable scalar tensor theory which can explain various transitional effects related to the behavior of the dark energy equation of state and the evolution of the Universe at large scales.

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Quintom dark energy with nonminimal coupling

Cited by 15 publications

References 48 publications

The past and future dynamics of quintom dark energy models

The past and future dynamics of quintom dark energy models

Generalised teleparallel quintom dark energy non-minimally coupled with the scalar torsion and a boundary term

Dynamical description of a quintom cosmological model nonminimally coupled with gravity

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