scholarly journals Braneworld Inspires Cosmological Implications of Barrow Holographic Dark Energy

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 268
Author(s):  
Shamaila Rani ◽  
Nadeem Azhar
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Speed Of Sound ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Accelerated Expansion ◽  
Late Time ◽  
Freezing And Thawing ◽  
Event Horizons

In the present manuscript, the evolution of the cosmic parameters and planes are being investigated in the framework of the DGP braneworld model. In this scenario, the interaction Γ between the Barrow holographic dark energy model (whose infrared cutoff scale is set by Hubble and event horizons) and pressureless dark matter are considered. We check the behavior of different cosmological parameters such as Hubble, equation of state, deceleration and squared speed of sound from the early matter-dominated era until the late-time acceleration. It is found that the range of Hubble parameter lies in the interval 95−35+35 (for Hubble horizon) and 97−23+23 (for event horizon). For both horizons, the equation of state parameter favors the phantom dominant era as well as the ΛCDM model while the deceleration parameter illustrates the accelerated expansion of the universe. Furthermore, stability of the underlying model is found through squared speed of sound. Furthermore, it is observed that ω−ωϑ′ plane corresponds to freezing and thawing region for Hubble and event horizons, respectively. Furthermore, statefinder plane shows the ΛCDM and Chaplygin gas behavior for both models. Finally, we investigate the thermodynamical nature of the underlying model through Barrow entropy as horizon entropy and found validity for both horizons.

scholarly journals Interacting Rényi Holographic Dark Energy in the Brans-Dicke Theory

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Vipin Chandra Dubey ◽  
Umesh Kumar Sharma ◽  
Abdulla Al Mamon
Keyword(s):  
Dark Energy ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Accelerated Expansion ◽  
Density Parameter ◽  
Late Time ◽  
Dark Energy Density ◽  
Expansion Phase ◽  
The Stability

In this work, we construct an interacting model of the Rényi holographic dark energy in the Brans-Dicke theory of gravity using Rényi entropy in a spatially flat Friedmann-Lemaître-Robertson-Walker Universe considering the infrared cut-off as the Hubble horizon. In this setup, we then study the evolutionary history of some important cosmological parameters, in particular, deceleration parameter, Hubble parameter, equation of state parameter, and Rényi holographic dark energy density parameter in both nonflat Universe and flat Universe scenarios and also observe satisfactory behaviors of these parameters in the model. We find that during the evolution, the present model can give rise to a late-time accelerated expansion phase for the Universe preceded by a decelerated expansion phase for both flat and nonflat cases. Moreover, we obtain ω D → − 1 as z → − 1 , which indicates that this model behaves like the cosmological constant at the future. The stability analysis for the distinct estimations of the Rényi parameter δ and coupling coefficient b 2 has been analyzed. The results indicate that the model is stable at the late time.

scholarly journals Analysis off(R)Theory Corresponding to NADE and NHDE

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
M. Sharif ◽  
M. Zubair
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Deceleration Parameter ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Future Evolution ◽  
Energy Models ◽  
Equation Of State Parameter ◽  
Effective Description

We develop the connection off(R)theory with new agegraphic and holographic dark energy models. The functionf(R)is reconstructed regarding thef(R)theory as an effective description for these dark energy models. We show the future evolution offand conclude that these functions represent distinct pictures of cosmological eras. The cosmological parameters such as equation of state parameter, deceleration parameter, statefinder diagnostic, andw−w′analysis are investigated which assure the evolutionary paradigm off.

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.

scholarly journals Cosmological aspects of sound speed parameterizations in fractal universe

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
Abdul Jawad ◽  
Sadaf Butt ◽  
Shamaila Rani ◽  
Khadija Asif
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Speed Of Sound ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Graphical Analysis ◽  
Eos Parameter ◽  
Energy Models ◽  
Equation Of State Parameter ◽  
The Universe

AbstractIn the framework of fractal universe, the unified models of dark energy and dark matter are being presented with the background of homogenous and isotropic FLRW geometry. The aspects of fractal cosmology helps in better understanding of the universe in different dimensions. Relationship between the squared speed of the sound and the equation of state parameter is the key feature of these models. We have used constant as well as variable forms of speed of sound and express it as a function of equation of state parameter. By utilizing the four different forms of speed of sound, we construct the energy densities and pressures for these models and then various cosmological parameters like hubble parameter, EoS parameter, deceleration parameter and Om- diagnostic are investigated. Graphical analysis of these parameters show that in most of the cases EoS parameters and trajectories of Om-diagnostic corresponds to the quintessence like nature of the universe and the deceleration parameters represent accelerated and decelerated phase. In the end, we remark that cosmological analysis of these models indicates that these models correspond to different well known dark energy models.

Power-law entropy-corrected new holographic dark energy in Brans–Dicke cosmology

2015 ◽  
Vol 93 (4) ◽  
pp. 475-480 ◽  
Author(s):  
Bharat Borah ◽  
M. Ansari
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Power Law ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Dark Energy Density ◽  
Cosmological Application ◽  
Expansion Of The Universe ◽  
Limiting Case

The purpose of this paper is to study power-law entropy-corrected holographic dark energy (PLECHDE) in the framework of Brans–Dicke cosmology with Granda–Oliveros (G-O) IR-cutoff. Considering the interacting and non-interacting scenario of PLECHDE with dark matter, we investigate the cosmological implications of this model in detail. We obtain the equation of state parameter, deceleration parameter, and evolution of dark energy density to explain expansion of the universe. We also determine these parameters for Ricci scale. We extend our study of the power-law entropy-corrected agegraphic dark energy model and calculate some cosmological parameters. Further, we show that the results that we calculate have good compatibility with previous work and matches it in the limiting case. Finally, we find a cosmological application of our work by evaluating the equation of state of dark energy for low red-shift.

Generalized ghost Tsallis holographic dark energy model in RS-II braneworld and dynamical Chern-Simons modified gravity

2020 ◽  
Vol 17 (08) ◽  
pp. 2050124
Author(s):  
Abdul Jawad ◽  
Sabir Hussain ◽  
Shamaila Rani ◽  
Saba Qummer
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Modified Gravity ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Frw Universe ◽  
Om Diagnostic ◽  
Equation Of State Parameter ◽  
Chern Simons

In this paper, we studied the cosmological implications of generalized ghost Tsallis holographic dark energy in the framework of Randall–Sundrum II braneworld and Chern–Simons modified gravity in flat FRW universe. We discuss the cosmological parameters like equation of state parameter, deceleration parameter, squared speed of sound, Om-diagnostic and planes like evolving equation of state parameter and statefinders. These models yield useful results in this context.

scholarly journals Cosmological Analysis of Dynamical Chern-Simons Modified Gravity via Dark Energy Scenario

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Abdul Jawad ◽  
Shamaila Rani
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Speed Of Sound ◽  
Modified Gravity ◽  
Cold Dark Matter ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Pilgrim Dark Energy ◽  
Energy Scenario ◽  
Chern Simons

The purpose of this paper is to study the cosmological evolution of the universe in the framework of dynamical Chern-Simons modified gravity. We take pilgrim dark energy model with Hubble and event horizons in interacting scenario with cold dark matter. For this scenario, we discuss cosmological parameters such as Hubble and equation of state and cosmological plane likeωϑ-ωϑ′and squared speed of sound. It is found that Hubble parameter approaches the ranges75-0.5+0.5(foru=2) and (74, 74.30) (foru=1,-1,-2) for Hubble horizon pilgrim dark energy. It implies the ranges74.80-0.005+0.005(foru=2) and (73.4, 74) (foru=-2) for event horizon pilgrim dark energy. The equation of state parameter provides consistent ranges with different observational schemes. Also,ωϑ-ωϑ′planes lie in the range (ωϑ=-1.13-0.25+0.24,ωϑ′<1.32). The squared speed of sound shows stability for all present models in the present scenario. We would like to mention here that our results of various cosmological parameters show consistency with different observational data like Planck, WP, BAO,H0, SNLS, and WMAP.

Cosmological evolution of non-interacting and interacting holographic dark energy model in Brans–Dicke theory

2018 ◽  
Vol 15 (07) ◽  
pp. 1850124 ◽  
Author(s):  
Milan Srivastava ◽  
C. P. Singh
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Deceleration Parameter ◽  
Holographic Dark Energy ◽  
Coupling Parameter ◽  
State Parameter ◽  
Late Time ◽  
Coincidence Problem ◽  
Logarithmic Form ◽  
Equation Of State Parameter

The purpose of this paper is to study the dynamics of non-interacting and interacting holographic dark energy (HDE) models in the framework of Brans–Dicke (BD) cosmology. As system’s infrared cutoff, we consider the future event horizon. The scalar function of BD theory is assumed to be a logarithmic form of scale factor, which is claimed to avoid a constant result for deceleration parameter. We investigate the cosmological implications of this model in detail. We obtain the time-dependent equation of state parameter and deceleration parameter which describe the phase transition of the Universe. We observe that the model explains the early time inflation and late time acceleration including matter-dominated phase. It is also observed that the equation of state parameter may cross phantom divide line in late time evolution. The cosmic coincidence problem is also discussed for both the models. We observe that this logarithmic form of Brans–Dicke scalar field is more appropriate to achieve a less acute coincidence problem in non-interacting model whereas a soft coincidence can be achieved if coupling parameter in interacting model has small value.

scholarly journals Phase space analysis and singularity classification for linearly interacting dark energy models

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Muhsin Aljaf ◽  
Daniele Gregoris ◽  
Martiros Khurshudyan
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Late Time ◽  
De Sitter ◽  
Effective Equation ◽  
De Sitter Universe ◽  
Friedmann Cosmological Models ◽  
Interacting Dark Energy Models

Abstract In this paper, applying the Hartman–Grobman theorem we carry out a qualitative late-time analysis of some unified dark energy-matter Friedmann cosmological models, where the two interact through linear energy exchanges, and the dark energy fluid obeys to the dynamical equation of state of Redlich–Kwong, Modified Berthelot, and Dieterici respectively. The identification of appropriate late-time attractors allows to restrict the range of validity of the free parameters of the models under investigation. In particular, we prove that the late-time attractors which support a negative deceleration parameter correspond to a de Sitter universe. We show that the strength of deviation from an ideal fluid for the dark energy does not influence the stability of the late-time attractors, as well as the values of all the cosmological parameters at equilibrium, but for the Hubble function (which represents the age of the universe). Our analysis also shows that a singularity in the effective equation of state parameter for the dark energy fluid is not possible within this class of models.

Study of Tsallis, Rényi and Sharma–Mittal holographic dark energies for entropy corrected modified field equations in Hořava–Lifshitz gravity

2020 ◽  
Vol 17 (11) ◽  
pp. 2050170
Author(s):  
Sayani Maity ◽  
Ujjal Debnath
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Speed Of Sound ◽  
Cold Dark Matter ◽  
State Parameter ◽  
Accelerated Expansion ◽  
Field Equations ◽  
Frw Universe ◽  
Equation Of State Parameter ◽  
The Universe

The purpose of this work is to study the Tsallis, Rényi and Sharma–Mittal holographic dark energy models in order to evaluate the accelerated expansion of the Universe. In this regard, we consider the modified field equations for logarithmic and power law versions of entropy corrected models in FRW Universe filled with interacting dark energy and cold dark matter within the framework of Hořava–Lifshitz gravity. Employing the Nojiri and Odintsov (NO) cut-off as infrared cutoff, we explore the nature of the different cosmological quantities like the equation of state parameter, squared speed of sound and [Formula: see text]–[Formula: see text] cosmological plane during the cosmic evolution. The equation of state parameter shows the different stages of the evolution of the Universe for the considered models. By analyzing the cosmological plane [Formula: see text]–[Formula: see text], we obtain the freezing region for these models. Also, due to the study of squared speed of sound, we show the classically stable behavior of the considered models.

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