Thermodynamics of Interacting new Agegraphic Dark Energy and Dark Matter Due to Bianchi Type I Model

We have studied the interacting and non-interacting dark energy and dark matter in the spatially homogenous and anisotropic Bianchi type-I model in the Brans-Dicke theory of gravitation. The field equations have been solved (i) by using power-law relation and (ii) by assuming scale factor in terms of redshift. Here we have considered two cases of an interacting and non-interacting dark energy scenario and obtained general results. It has been found that for suitable choice of interaction between dark energy and dark matter we can avoid the coincidence problem which appears in the ΛCDM model. Some physical aspects and stability of the models are discussed in detail. The statefinder diagnostic pair, i.e., {r,s}, is adopted to differentiate our dark energy models.

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BIANCHI TYPE I COSMOLOGIES WITH THE DARK MATTER IN THE BACKGROUND OF DARK ENERGY

International Journal of Modern Physics D ◽

10.1142/s0218271807011061 ◽

2007 ◽

Vol 16 (11) ◽

pp. 1761-1768 ◽

Cited By ~ 3

Author(s):

TANWI BANDYOPADHYAY ◽

NARAYAN CHANDRA CHAKRABORTY ◽

SUBENOY CHAKRABORTY

Keyword(s):

Dark Matter ◽

Dark Energy ◽

Bianchi Type ◽

Type I ◽

Bianchi Type I ◽

Cosmological Solutions ◽

Dust Fluid

This paper deals with the cosmological study of the Bianchi type I model made of dust fluid in the background of dark energy. Cosmological solutions are obtained for the following four cases: (i) only with dark matter; (ii) only with dark energy; (iii) both dark matter and dark energy are present but without interaction; (iv) interactive dark matter and dark energy.

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Anisotropic models with generalized hybrid expansion in Brans–Dicke theory of gravity

International Journal of Geometric Methods in Modern Physics ◽

10.1142/s0219887821501413 ◽

2021 ◽

pp. 2150141

Author(s):

S. Surendra Singh ◽

Yohenba Soibam

Keyword(s):

Dark Matter ◽

Dark Energy ◽

Power Law ◽

Bianchi Type ◽

Scale Factor ◽

Late Time ◽

Type I ◽

Coincidence Problem ◽

Bianchi Type I ◽

Average Scale Factor

The hybrid expansion law (HEL) for average scale factor that yields power-law and exponential-law cosmologies is considered in spatially homogenous and anisotropic Bianchi type-I model in the context of Brans–Dicke (BD) Theory of gravitation. The solutions of the field equations have been calculated by assuming the power-law expression between the average scale factor [Formula: see text] and scalar field ([Formula: see text]). We studied both interacting and non-interacting forms of dark energy and dark matter and obtained respective solutions. The energy density [Formula: see text] decreases with time while energy densities [Formula: see text] increases with time. In both the cases, the physical acceptability and stability of the models are also studied. The coincidence problem in [Formula: see text]CDM model can be ruled out with proper choice of coupling between dark matter (DM) and dark energy (DE). We also discussed the physical behaviors of the derived models with the current observations applied to late-time acceleration and beginning of the universe. In this model, it is observed that our HEL Bianchi type I universe is highly anisotropic in the beginning of universe and becomes isotropic and overlaps with flat [Formula: see text]CDM model at late times.

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Constraints on the Ricci dark energy cosmologies in Bianchi type I model

International Journal of Geometric Methods in Modern Physics ◽

10.1142/s021988782150095x ◽

2021 ◽

pp. 2150095

Author(s):

H. Hossienkhani ◽

N. Azimi ◽

H. Yousefi

Keyword(s):

Dark Energy ◽

Dark Energy Model ◽

Bianchi Type ◽

Energy Model ◽

Accelerated Expansion ◽

Likelihood Method ◽

Type I ◽

Ricci Dark Energy ◽

Bianchi Type I ◽

The Impact

The impact of anisotropy on the Ricci dark energy cosmologies is investigated where it is assumed that the geometry of the universe is described by Bianchi type I (BI) metric. The main goal is to determine the astrophysical constraints on the model by using the current available data as type Ia supernovae (SNIa), the Baryon Acoustic Oscillation (BAO), and the Hubble parameter [Formula: see text] data. In this regard, a maximum likelihood method is applied to constrain the cosmological parameters. Combining the data, it is found out that the allowed range for the density parameter of the model stands in [Formula: see text]. With the help of the Supernova Legacy Survey (SNLS) sample, we estimate the possible dipole anisotropy of the Ricci dark energy model. Then, by using a standard [Formula: see text] minimization method, it is realized that the transition epoch from early decelerated to current accelerated expansion occurs faster in Ricci dark energy model than [Formula: see text]CDM model. The results indicate that the BI model for the Ricci dark energy is consistent with the observational data.

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