https://doi.org/10.1140/epjc/s10052-019-7390-3
Regular Article - Theoretical Physics
Constraints on barotropic dark energy models by a new phenomenological q(z) parameterization
1
Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Nuevo León, San Nicolás de los Garza, Mexico
2
Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. postal 106, CP 22800, Ensenada, BC, Mexico
3
Instituto de Física y Astronomía, Universidad de Valparaíso, Avenida Gran Bretaña, 1111, Valparaiso, Chile
* e-mail: jaime.romangrz@uanl.edu.mx
Received:
5
July
2019
Accepted:
9
October
2019
Published online:
5
November
2019
In this paper, we propose a new phenomenological two parameter parameterization of q(z) to constrain barotropic dark energy models by considering a spatially flat Universe, neglecting the radiation component, and reconstructing the effective equation of state (EoS). This two free-parameter EoS reconstruction shows a non-monotonic behavior, pointing to a more general fitting for the scalar field models, like thawing and freezing models. We constrain the q(z) free parameters using the observational data of the Hubble parameter obtained from cosmic chronometers, the joint-light-analysis Type Ia Supernovae (SNIa) sample, the Pantheon (SNIa) sample, and a joint analysis from these data. We obtain, for the joint analysis with the Pantheon (SNIa) sample a value of q(z) today, , and a transition redshift,
(when the Universe change from an decelerated phase to an accelerated one). The effective EoS reconstruction and the
–
plane analysis point towards a transition over the phantom divide, i.e.
, which is consistent with a non parametric EoS reconstruction reported by other authors.
© The Author(s), 2019