Sharma–Mittal holographic dark energy model in conharmonically flat space-time

2020 ◽  
Vol 18 (01) ◽  
pp. 2150002
Author(s):  
Vipin Chandra Dubey ◽  
Umesh Kumar Sharma ◽  
Anirudh Pradhan
Keyword(s):  
Dark Energy ◽  
Cosmological Parameters ◽  
Field Potential ◽  
Flat Space ◽  
Accelerated Expansion ◽  
Frw Universe ◽  
Eos Parameter ◽  
Expansion Of The Universe ◽  
Quintessence Field ◽  
The Universe

In this work, we explore the accelerated expansion of the conharmonically flat space in relation to an isotropic and spatially homogeneous Friedmann–Robertson–Walker (FRW) universe through a newly proposed dark energy (DE) model namely Sharma–Mittal holographic DE (SMHDE) by taking Hubble horizon as an IR cut-off and also by considering the deceleration parameter as a linear function of Hubble parameter as [Formula: see text], where [Formula: see text] and [Formula: see text] are arbitrary constants. The analysis of different cosmological parameters, equation of state (EoS) parameter, squared speed of sound, statefinder, [Formula: see text] pair, and quintessence field model has been calculated and discussed in detail. Analyzing the behavior of such cosmological parameters graphically, it is found that the SMHDE model can lead to the accelerated expansion of the universe at present epoch. We have also reconciled the DE with scalar field potential. For this analysis, we take into account the quintessence field for this reconstruction.

Tsallis holographic dark energy models in axially symmetric space time

2020 ◽  
Vol 17 (01) ◽  
pp. 2050011 ◽  
Author(s):  
Vipin Chandra Dubey ◽  
Ambuj Kumar Mishra ◽  
Shikha Srivastava ◽  
Umesh Kumar Sharma
Keyword(s):  
Dark Energy ◽  
Scalar Field ◽  
Holographic Dark Energy ◽  
Field Potential ◽  
Accelerated Expansion ◽  
Anisotropic Universe ◽  
Axially Symmetric ◽  
Eos Parameter ◽  
Quintessence Field ◽  
The Universe

In this work, we have examined the behavior of Bianchi-I (axially symmetric) matter-dominated and the anisotropic Universe with the proposed dark energy, Tsallis holographic dark energy (THDE), with the Hubble horizon as infrared cut-off [Tavayef et al., Tsallis holographic dark energy, Phys. Lett. B 781 (2018) 195–200]. The Universe evolution from matter-dominated epoch to dark energy dominated epoch is described by our proposed THDE model. The EoS parameter in our THDE model explains the evolution of the Universe according to the value of nonextensive or Tsallis parameter [Formula: see text], phantom era ([Formula: see text]) or quintom (phantom line crossing) and the quintessence era ([Formula: see text]), before reaching to completely dark energy-dominated era in the future. Additionally, we also plan to reconcile the dark energy by the method of reconstructing the evolution of the scalar field potential. For the analysis, we take into account the quintessence field and phantom scalar field for this reconstruction, which at present shows the accelerated expansion.

scholarly journals Reconstruction of quintessence field for the THDE with swampland correspondence in f(R,T) gravity

2020 ◽  
pp. 2150031 ◽  
Author(s):  
Umesh Kumar Sharma
Keyword(s):  
Dark Energy ◽  
Holographic Dark Energy ◽  
Accelerated Expansion ◽  
Eos Parameter ◽  
Expansion Of The Universe ◽  
Hubble Horizon ◽  
Quintessence Field ◽  
The Universe ◽  
Friedmann Robertson Walker ◽  
Quintessence Model

In the present work, we construct the Tsallis holographic quintessence model of dark energy in [Formula: see text] gravity with Hubble horizon as infrared (IR) cut-off. In a flat Friedmann–Robertson–Walker (FRW) background, the correspondence among the energy density of the quintessence model with the Tsallis holographic density permits the reconstruction of the dynamics and the potentials for the quintessence field. The suggested Hubble horizon IR cut-off for the Tsallis holographic dark energy (THDE) density acts for two specific cases: (i) THDE 1 and (ii) THDE 2. We have reconstructed the Tsallis holographic quintessence model in the region [Formula: see text] for the equation of state (EoS) parameter for both the cases. we investigate the behavior of several well-known statefinder quantities, like the deceleration parameter, the jerk and the parameter [Formula: see text]. In addition, the quintessence phase of the THDE models is analyzed with swampland conjecture to describe the accelerated expansion of the Universe.

ENTROPY CORRECTED HOLOGRAPHIC DARK ENERGY f(T) GRAVITY MODEL

2014 ◽  
Vol 29 (02) ◽  
pp. 1450015 ◽  
Author(s):  
M. SHARIF ◽  
SHAMAILA RANI
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Phase Plane ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
Accelerated Expansion ◽  
Statefinder Parameters ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Evolution Trajectory

This paper is devoted to study the power-law entropy corrected holographic dark energy (ECHDE) model in the framework of f(T) gravity. We assume infrared (IR) cutoff in terms of Granda–Oliveros (GO) length and discuss the constructed f(T) model in interacting as well as in non-interacting scenarios. We explore some cosmological parameters like equation of state (EoS), deceleration, statefinder parameters as well as ωT–ωT′ analysis. The EoS and deceleration parameters indicate phantom behavior of the accelerated expansion of the universe. It is mentioned here that statefinder trajectories represent consistent results with ΛCDM limit, while evolution trajectory of ωT–ωT′ phase plane does not approach to ΛCDM limit for both interacting and non-interacting cases.

Kaluza–Klein minimally interacting dark energy model in the presence of massive scalar field

2021 ◽  
Vol 36 (08) ◽  
pp. 2150054
Author(s):  
K. Dasu Naidu ◽  
Y. Aditya ◽  
R. L. Naidu ◽  
D. R. K. Reddy
Keyword(s):  
Dark Energy ◽  
Scalar Field ◽  
Cosmological Parameters ◽  
Accelerated Expansion ◽  
Massive Scalar ◽  
Field Equations ◽  
Eos Parameter ◽  
Massive Scalar Field ◽  
The Universe ◽  
Kaluza Klein

In this paper, our purpose is to discuss the dynamical aspects of Kaluza–Klein five-dimensional cosmological model filled with minimally interacting baryonic matter and dark energy (DE) in the presence of an attractive massive scalar field. We obtain a determinate solution of the Einstein field equations using (i) a relation between the metric potentials and (ii) a power law relation between the average scale factor of the universe and the massive scalar field. We have determined scalar field, matter energy density, DE density, equation of state (EoS) [Formula: see text], deceleration [Formula: see text] and statefinder [Formula: see text] parameters of our model. We also develop [Formula: see text]–[Formula: see text] phase, squared sound speed, statefinders and [Formula: see text]–[Formula: see text] planes in the evolving universe. It is observed that the EoS parameter exhibits quintom-like behavior from quintessence to phantom epoch by crossing the vacuum era of the universe. The squared speed of sound represents the instability of the model, whereas the [Formula: see text]–[Formula: see text] plane shows both thawing and freezing regions. The [Formula: see text]CDM limit is attained in both [Formula: see text]–[Formula: see text] and statefinder planes. We have also discussed the cosmological importance of the above parameters with reference to modern cosmology. It is found that the dynamics of these cosmological parameters indicate the accelerated expansion of the universe which is consistent with the current cosmological observations.

scholarly journals Barrow HDE model for statefinder diagnostic in FLRW universe

2021 ◽  
pp. 2150030
Author(s):  
Anirudh Pradhan ◽  
Archana Dixit ◽  
Vinod Kumar Bhardwaj
Keyword(s):  
Dark Energy ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Accelerated Expansion ◽  
Density Parameter ◽  
Phantom Divide ◽  
Phantom Divide Line ◽  
Expansion Of The Universe ◽  
Flrw Universe ◽  
The Universe

We have analyzed the Barrow holographic dark energy (BHDE) in the framework of flat FLRW universe by considering the various estimations of Barrow exponent △. Here, we define BHDE, by applying the usual holographic principle at a cosmological system, for utilizing the Barrow entropy rather than the standard Bekenstein–Hawking. To understand the recent accelerated expansion of the universe, consider the Hubble horizon as the IR cutoff. The cosmological parameters, especially the density parameter [Formula: see text], the equation of the state parameter [Formula: see text], energy density [Formula: see text] and the deceleration parameter [Formula: see text] are studied in this paper and found the satisfactory behaviors. Moreover we additionally focus on the two geometric diagnostics, the statefinder [Formula: see text] and [Formula: see text] to discriminant BHDE model from the [Formula: see text]CDM model. Here we determined and plotted the trajectories of evolution for statefinder [Formula: see text], [Formula: see text] and [Formula: see text] diagnostic plane to understand the geometrical behavior of the BHDE model by utilizing Planck 2018 observational information. Finally, we have explored the new Barrow exponent △, which strongly affects the dark energy equation of state that can lead it to lie in the quintessence regime, phantom regime and exhibits the phantom-divide line during the cosmological evolution.

scholarly journals Observational constraints and stability in viscous gravity

2020 ◽  
Vol 98 (12) ◽  
pp. 1119-1124
Author(s):  
T. Mirzaei Rezaei ◽  
Alireza Amani ◽  
E. Yusofi ◽  
S. Rouhani ◽  
M.A. Ramzanpour
Keyword(s):  
Dark Energy ◽  
Cosmological Parameters ◽  
Teleparallel Gravity ◽  
System Stability ◽  
Accelerated Expansion ◽  
Tetrad Field ◽  
Dark Energy Component ◽  
Walker Metric ◽  
Expansion Of The Universe ◽  
The Universe

In this paper, we study the [Formula: see text] gravity model in the presence of bulk viscosity by the flat Friedmann–Robertson–Walker metric. The field equation is obtained by teleparallel gravity with a tetrad field. The universe components are considered matter and dark energy, with the dark energy component associated with viscous [Formula: see text] gravity. After calculating the Friedmann equations, we obtain the energy density, pressure, and equation of state of dark energy in terms of the redshift parameter. Afterward, we plot the corresponding cosmological parameters versus the redshift parameter and examine the accelerated expansion of the universe. In the end, we explore the system stability using a function called the speed sound parameter.

Entropy corrected holographic dark energy models in modified gravity

2017 ◽  
Vol 26 (04) ◽  
pp. 1750040 ◽  
Author(s):  
Abdul Jawad ◽  
Nadeem Azhar ◽  
Shamaila Rani
Keyword(s):  
Dark Energy ◽  
Modified Gravity ◽  
Cold Dark Matter ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
Second Law Of Thermodynamics ◽  
Accelerated Expansion ◽  
Eos Parameter ◽  
Generalized Second Law ◽  
Expansion Of The Universe

We consider the power law and the entropy corrected holographic dark energy (HDE) models with Hubble horizon in the dynamical Chern–Simons modified gravity. We explore various cosmological parameters and planes in this framework. The Hubble parameter lies within the consistent range at the present and later epoch for both entropy corrected models. The deceleration parameter explains the accelerated expansion of the universe. The equation of state (EoS) parameter corresponds to quintessence and cold dark matter ([Formula: see text]CDM) limit. The [Formula: see text] approaches to [Formula: see text]CDM limit and freezing region in both entropy corrected models. The statefinder parameters are consistent with [Formula: see text]CDM limit and dark energy (DE) models. The generalized second law of thermodynamics remain valid in all cases of interacting parameter. It is interesting to mention here that our results of Hubble, EoS parameter and [Formula: see text] plane show consistency with the present observations like Planck, WP, BAO, [Formula: see text], SNLS and nine-year WMAP.

Cosmological study in loop quantum cosmology through dark energy model

2017 ◽  
Vol 26 (02) ◽  
pp. 1750007
Author(s):  
Abdul Jawad ◽  
Shamaila Rani ◽  
Ines G. Salako ◽  
Faiza Gulshan
Keyword(s):  
Dark Energy ◽  
Quantum Cosmology ◽  
Cold Dark Matter ◽  
Cosmological Parameters ◽  
Chaplygin Gas ◽  
Accelerated Expansion ◽  
Loop Quantum Cosmology ◽  
Eos Parameter ◽  
Pilgrim Dark Energy ◽  
Expansion Of The Universe

The interacting generalized ghost version of pilgrim dark energy (GGPDE) is discussed in the framework of loop quantum cosmology (LQC). We analyze the behavior of cosmological parameters (Hubble, equation of state (EoS), deceleration) and cosmological planes ([Formula: see text] and [Formula: see text]-[Formula: see text]) in the present scenario ([Formula: see text] represents the EoS parameter and [Formula: see text] indicates the evolution of the EoS parameter, [Formula: see text],[Formula: see text] are statefinder parameters). It is observed that the deceleration parameter corresponds to the accelerated expansion of the universe. The EoS parameter lies in vacuum and phantom regions for all cases of [Formula: see text] (pilgrim dark energy (PDE) parameter). The [Formula: see text] plane lies in thawing region for all cases of [Formula: see text]. The [Formula: see text] plane corresponds to [Formula: see text] cold dark matter (CDM) and Chaplygin gas model. We have also mentioned the constraints on calculated cosmological parameters and found that all the trajectories of cosmological parameters and planes show the consistence behavior with the observational schemes.

Kantowski–Sachs universe with dark energy fluid and massive scalar field

2020 ◽  
Vol 98 (11) ◽  
pp. 993-998
Author(s):  
K. Deniel Raju ◽  
M.P.V.V. Bhaskara Rao ◽  
Y. Aditya ◽  
T. Vinutha ◽  
D.R.K. Reddy
Keyword(s):  
Dark Energy ◽  
Scalar Field ◽  
Cosmological Parameters ◽  
Accelerated Expansion ◽  
Massive Scalar ◽  
Field Equations ◽  
Massive Scalar Field ◽  
Anisotropic Dark Energy ◽  
Expansion Of The Universe ◽  
The Universe

This study is mainly concerned with a spatially homogeneous and anisotropic Kantowski–Sachs cosmological model with anisotropic dark energy fluid and massive scalar field. We solve the field equations using (i) the shear scalar proportionality to the expansion scalar and (ii) a mathematical condition that is a consequence of the power law between the scalar field and the average scale factor of the universe, and the corresponding dark energy model is presented. The cosmological parameters of the model are computed and discussed, as well as the relevance of its dynamical aspects to the recent scenario of the accelerated expansion of the universe.

The scalar field models of Tsallis holographic dark energy with Granda-Oliveros cut-off in modified gravity

2021 ◽  
Author(s):  
Anirudh Pradhan ◽  
Gunjan Varshney ◽  
Umesh Kumar Sharma
Keyword(s):  
Dark Energy ◽  
Energy Density ◽  
Holographic Dark Energy ◽  
Scalar Fields ◽  
Accelerated Expansion ◽  
Model Parameters ◽  
Frw Universe ◽  
Dark Energy Density ◽  
Eos Parameter ◽  
Expansion Of The Universe

This research explores the Tsallis holographic quintessence, k-essence, and tachyon model of dark energy in the modified f(R, T) gravity framework with Granda-Oliveros cutoff. We have analyzed the energy density through ρΛ = (αH<sup>2</sup> + βH)<sup>-δ+2</sup>. We study the correspondence between the quintessence, k-essence, and tachyon energy density with the Tsallis holographic dark energy density in a flat FRW Universe. The reconstruction is performed for the different values of Tsallis parameter δ in the region of ωΛ > -1 for the EoS parameter. This correspondence allows reconstructing the potentials and the dynamics for the scalar fields models, if we set some constraints for the model parameters, which describe the accelerated expansion of the Universe.

Sign in / Sign up

Export Citation Format

Share Document