Quintom phase-space: Beyond the exponential potential

León, Genly; Leyva, Yoelsy; Socorro, J.

doi:10.1016/j.physletb.2014.03.053

Cited by 55 publications

(59 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This ansatz avoids the degeneracy problem associated with the case when the bulk viscosity is taken as ζ j = ζ j (H ) [20]. However, in [22], the same scenario was studied, from the dynamical system point of view, finding that viscous phantom solutions with stable behavior are not allowed in the framework of complete cosmological dynamics [21,30]. In the present paper we work along these lines by including an interaction between the dark matter and the dark energy.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Bulk viscosity, interaction and the viability of phantom solutions

Leyva¹,

Sepúlveda²

2017

Eur. Phys. J. C

Self Cite

View full text Add to dashboard Cite

We study the dynamics of a bulk viscosity model in the Eckart approach for a spatially flat FriedmannRobertson-Walker (FRW) Universe. We have included radiation and dark energy, assumed as perfect fluids, and dark matter treated as an imperfect fluid having bulk viscosity. We also introduce an interaction term between the dark matter and dark energy components. Considering that the bulk viscosity is proportional to the dark matter energy density and imposing a complete cosmological dynamics, we find bounds on the bulk viscosity in order to reproduce a matterdominated era (MDE). This constraint is independent of the interaction term. Some late time phantom solutions are mathematically possible. However, the constraint imposed by a MDE restricts the interaction parameter, in the phantom solutions, to a region consistent with a null value, eliminating the possibility of late time stable solutions with w < −1. From the different cases that we study, the only possible scenario, with bulk viscosity and interaction term, belongs to the quintessence region. In the latter case, we find bounds on the interaction parameter compatible with latest observational data.

show abstract

Section: Introductionmentioning

confidence: 99%

“…We focus our attention on a particular form for the interaction term between the dark matter and dark energy components. A detailed discussion as regards the viability of a complete cosmological dynamics [21,30] is provided. Important constraints on the bulk viscosity and interaction parameter are obtained.…”

Section: Introductionmentioning

confidence: 99%

Bulk viscosity, interaction and the viability of phantom solutions

Leyva¹,

Sepúlveda²

2017

Eur. Phys. J. C

Self Cite

View full text Add to dashboard Cite

show abstract

“…We discuss the equivalent conformal theories in the Einstein frame for the two cosmological models of our consideration. We shall see that in the Einstein frame the two models (2), (3) becomes the sigma model [20,21], also known as Chiral cosmology [22][23][24] and the quintom model [26][27][28][29][30].…”

Section: Conformal Equivalencementioning

confidence: 99%

Conservation laws and exact solutions in Brans–Dicke cosmology with a scalar field

Paliathanasis

2019

Gen Relativ Gravit

View full text Add to dashboard Cite

Scalar-tensor theories have drawn the attention of cosmologist for the past few years because they can provide mechanism to explain the observable phenomena. Moreover, the results of scalar-tensor theories can be applied in higher-order theories of gravity. In this work, we consider a Brans-Dicke scalar field cosmological model that includes a second scalar field minimally coupled to gravity. For the second scalar field we consider the two cases that there exist and there is not any interaction with the Brans-Dicke scalar field. For the two models of our consideration we prove the existence of scaling and de Sitter solutions. Furthermore, we perform an Obsiannikov's classification for the field equations, where we find all the point and contact transformations which leave the gravitational Action Integral invariant. Conservation laws are determined and we show how these can be applied to infer about the integrability of the cosmological models and find new analytic solutions. 95.35.+d, 95.36.+x

show abstract

“…In this case the dynamical systems tools come to our rescue. The dynamical systems theory provides powerful tools which are commonly used in cosmology to extract essential information on the dynamical properties of a variety of cosmological models, in particular, those models where the scalar field plays a role [16,[24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43].…”

Section: What Do the Dynamical Systems Have To Say About The Brmentioning

confidence: 99%