Abstract
We derive modified classes of Chaplygin gas by using the formalism of Geometrothermodynamics. In particular, our strategy gives us extended versions of Chaplygin gas, providing a novel thermodynamic explanation. Thus, we show that our models correspond to systems with internal thermodynamic interaction. Bearing this in mind, we find new free parameters which are derived from thermodynamics and we give them an interpretation. To this end, we predict the range of values that every term can take in the context of homogeneous and isotropic universe. We also show that our new versions of modified Chaplygin gas can be interpreted as unified dark energy models, independently from the introduction of our new additional terms. Finally, we compare our theoretical scenarios through a fit on a grid based on the Union 2.1 compilation and we evaluate the growth factor of small perturbations. In this respect, we show that our model better adapts to the theoretical varLambda CDM value, namely gamma _{varLambda CDM}=frac{6}{11}, than previous versions of modified Cgaplygin gas. We show numerical constraints at late and early redshift domains, which turn out to be compatible with previous results on standard versions of Chaplygin gas models.
Highlights
A growing number of data surveys indicate that the observable universe is undergoing a phase of accelerated expansion [1,2,3,4,5,6,7,8,9,10]
We show that our new versions of modified Chaplygin gas can be interpreted as unified dark energy models, independently from the introduction of our new additional terms
We show that our model better adapts to the theoretical ΛCDM value, namely γΛC D M
Summary
A growing number of data surveys indicate that the observable universe is undergoing a phase of accelerated expansion [1,2,3,4,5,6,7,8,9,10]. Unified dark energy models and, in particular, the modified Chaplygin gas has the remarkable property of describing the dark sector of the universe through a single dark fluid, which passes from a matter-dominated era to a cosmological constant-dominated era [36–38]. Several papers discuss the behavior of the modified Chaplygin gas to reconcile the standard cosmological model with observations [39–42], a full explanation of the mechanism behind the origin of unified dark energy model is still lacking. We combine thermodynamic and geometric considerations in the GTD framework, and find out a new equation of state of the modified Chaplygin gas, which explains the recent cosmological observations.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
