scholarly journals Viscous dissipative Chaplygin gas dominated homogenous and isotropic cosmological models

2008 ◽  
Vol 77 (6) ◽  
Author(s):  
C. S. J. Pun ◽  
L. Á. Gergely ◽  
M. K. Mak ◽  
Z. Kovács ◽  
G. M. Szabó ◽  
...  
Keyword(s):  
Chaplygin Gas ◽  
Cosmological Models

scholarly journals Late Time Attractors of Some Varying Chaplygin Gas Cosmological Models

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 769
Author(s):  
Martiros Khurshudyan ◽  
Ratbay Myrzakulov
Keyword(s):  
Dark Energy ◽  
Gravitational Interaction ◽  
Chaplygin Gas ◽  
Cosmological Models ◽  
Late Time ◽  
Time Behavior ◽  
Coincidence Problem ◽  
Energy Models ◽  
Non Linear ◽  
Bayesian Machine Learning

The goal of this paper is to study new cosmological models where the dark energy is a varying Chaplygin gas. This specific dark energy model with non-linear EoS had been often discussed in modern cosmology. Contrary to previous studies, we consider new forms of non-linear non-gravitational interaction between dark matter and assumed dark energy models. We applied the phase space analysis allowing understanding the late time behavior of the models. It allows demonstrating that considered non-gravitational interactions can solve the cosmological coincidence problem. On the other hand, we applied Bayesian Machine Learning technique to learn the constraints on the free parameters. In this way, we gained a better understanding of the models providing a hint which of them can be ruled out. Moreover, the learning based on the simulated expansion rate data shows that the models cannot solve the H0 tension problem.

scholarly journals RASTALL COSMOLOGY

2012 ◽  
Vol 18 ◽  
pp. 67-76 ◽  
Author(s):  
JÚLIO C. FABRIS ◽  
OLIVER F. PIATTELLA ◽  
DAVI C. RODRIGUES ◽  
CARLOS E. M. BATISTA ◽  
MAHAMADOU H. DAOUDA
Keyword(s):  
Scalar Field ◽  
Observational Data ◽  
Canonical Form ◽  
Conservation Law ◽  
Chaplygin Gas ◽  
Cosmological Models ◽  
The Self ◽  
Generalized Chaplygin Gas ◽  
Field Representation ◽  
Theory Of Gravity

We review the difficulties of the generalized Chaplygin gas model to fit observational data, due to the tension between background and perturbative tests. We argue that such issues may be circumvented by means of a self-interacting scalar field representation of the model. However, this proposal seems to be successful only if the self-interacting scalar field has a non-canonical form. The latter can be implemented in Rastall's theory of gravity, which is based on a modification of the usual matter conservation law. We show that, besides its application to the generalized Chaplygin gas model, other cosmological models based on Rastall's theory have many interesting and unexpected new features.

Sign in / Sign up

Export Citation Format

Share Document