scholarly journals New holographic dark energy model inspired by the DGP braneworld

2016 ◽  
Vol 25 (02) ◽  
pp. 1650018 ◽  
Author(s):  
A. Sheykhi ◽  
M. H. Dehghani ◽  
S. Ghaffari
Keyword(s):  
Dark Energy ◽  
Energy Density ◽  
Holographic Dark Energy ◽  
Apparent Horizon ◽  
Brane Cosmology ◽  
Eos Parameter ◽  
New Model ◽  
Hubble Radius ◽  
Area Law ◽  
Dgp Braneworld

The energy density of the holographic dark energy (HDE) is based on the area law of entropy, and thus any modification of the area law leads to a modified holographic energy density. Inspired by the entropy expression associated with the apparent horizon of a Friedmann–Robertson–Walker (FRW) universe in DGP braneworld, we propose a new model for the HDE in the framework of DGP brane cosmology. We investigate the cosmological consequences of this new model and calculate the equation of state (EoS) parameter by choosing the Hubble radius, [Formula: see text], as the system’s IR cutoff. Our study show that, due to the effects of the extra dimension (bulk), the identification of IR cutoff with Hubble radius, can reproduce the present acceleration of the universe expansion. This is in contrast to the ordinary HDE in standard cosmology which leads to the zero EoS parameter in the case of choosing the Hubble radius as system’s IR cutoff in the absence of interaction between dark matter (DM) and dark energy (DE).

scholarly journals HOLOGRAPHIC DARK ENERGY AND VALIDITY OF THE GENERALIZED SECOND LAW OF THERMODYNAMICS IN THE DGP BRANEWORLD

2010 ◽  
Vol 25 (36) ◽  
pp. 3069-3079 ◽  
Author(s):  
JIBITESH DUTTA ◽  
SUBENOY CHAKRABORTY ◽  
M. ANSARI
Keyword(s):  
Dark Energy ◽  
Holographic Dark Energy ◽  
Apparent Horizon ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Fluid System ◽  
Generalized Second Law ◽  
The Universe ◽  
Two Fluid ◽  
Dgp Braneworld

In this paper, we investigate the validity of the generalized second law of thermodynamics (GSLT) in the DGP braneworld. The boundary of the universe is assumed to be enclosed by the dynamical apparent horizon or the event horizon. The universe is chosen to be homogeneous and isotropic and the validity of the first law has been assumed here. The matter in the universe is taken in the form of non-interacting two-fluid system: one component is the holographic dark energy and the other component is in the form of dust.

scholarly journals Tsallis holographic dark energy in fractal universe

2020 ◽  
Vol 35 (14) ◽  
pp. 2050107 ◽  
Author(s):  
S. Ghaffari ◽  
E. Sadri ◽  
A. H. Ziaie
Keyword(s):  
Dark Energy ◽  
Gamma Ray ◽  
Holographic Dark Energy ◽  
Accelerating Universe ◽  
Density Parameter ◽  
Late Time ◽  
Dark Energy Density ◽  
Eos Parameter ◽  
Deceleration Phase ◽  
Hubble Radius

We study the cosmological consequences of interacting Tsallis holographic dark energy model in the framework of the fractal universe in which the Hubble radius is considered as the IR cutoff. We derive the equation of state (EoS) parameter, deceleration parameter and the evolution equation for the Tsallis holographic dark energy density parameter. Our study shows that this model can describe the current accelerating universe in both non-interacting and interacting scenarios, and also a transition occurs from the deceleration phase to the accelerated phase at the late-time. Finally, we check the compatibility of free parameters of the model with the latest observational results by using the Pantheon supernovae data, eBOSS, 6df, BOSS DR12, CMB Planck 2015, Gamma-Ray Burst.

Cosmological implications of DGP braneworld via well-known holographic dark energy models

2016 ◽  
Vol 25 (14) ◽  
pp. 1650102 ◽  
Author(s):  
Shamaila Rani ◽  
Abdul Jawad
Keyword(s):  
Dark Energy ◽  
Observational Data ◽  
Speed Of Sound ◽  
Deceleration Parameter ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
Cosmic Acceleration ◽  
Eos Parameter ◽  
Current Scenario ◽  
Dgp Braneworld

The cosmological analysis is being studied in the present work in Dvali–Gabadadze–Porrati (DGP) braneworld scenario by taking various interacting modified holographic dark energy (HDE) models. We discuss the various cosmological parameters such as deceleration parameter, equation-of-state (EoS) parameter and squared speed of sound. It is found that the trajectories of deceleration parameter exhibit in accelerated phase of the universe for all models. The EoS parameter corresponds to various phases of cosmic acceleration like quintessence, vacuum, phantom and also exhibits consistency with observational data. The squared speed of sound also gives stability of models in the current scenario. The [Formula: see text] also gives consistent results with various observational schemes. The statefinders plane also exhibits the cosmic acceleration. It is interesting to remark here that some of our results shows consistency with observational data like WMAP+CMB+BAO+[Formula: see text]+SNe.

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.

scholarly journals Holographic dark energy from minimal supergravity

2016 ◽  
Vol 25 (04) ◽  
pp. 1650050 ◽  
Author(s):  
Ricardo C. G. Landim
Keyword(s):  
Dark Energy ◽  
Energy Density ◽  
Holographic Dark Energy ◽  
Dark Sector ◽  
Future Event ◽  
Two Fluids ◽  
Minimal Supergravity ◽  
Hubble Radius ◽  
Chiral Superfield ◽  
Future Event Horizon

We embed models of holographic dark energy (HDE) coupled to dark matter (DM) in minimal supergravity plus matter, with one chiral superfield. We analyze two cases. The first one has the Hubble radius as the infrared (IR) cutoff and the interaction between the two fluids is proportional to the energy density of the DE. The second case has the future event horizon as IR cutoff while the interaction is proportional to the energy density of both components of the dark sector.

scholarly journals Revisiting holographic dark energy in cyclic cosmology

2018 ◽  
Vol 96 (9) ◽  
pp. 1034-1041 ◽  
Author(s):  
A. Sheykhi ◽  
M. Tavayef ◽  
H. Moradpour
Keyword(s):  
Dark Energy ◽  
Energy Density ◽  
Cosmological Constant ◽  
Holographic Dark Energy ◽  
Mutual Interaction ◽  
Cyclic Universe ◽  
Big Rip ◽  
Hubble Radius ◽  
Contraction And Expansion

Considering the holographic dark energy (HDE) with two different infrared (IR) cutoffs, we study the evolution of a cyclic universe, which avoids the Big-Rip singularity. Our results show that, even in the absence of a mutual interaction between the cosmos sectors, the HDE model with the Hubble radius as IR cutoff can mimic a cosmological constant in the framework of a cyclic cosmology. In addition, we find that both the interacting and non-interacting universes may enter into a cycle of sequential contraction and expansion, if the Granda–Oliveros cutoff is chosen as the IR cutoff in the energy density of the HDE. We also investigate the instability of the model against perturbations and find the ranges of the parameters in which the model is stable.

scholarly journals Physical Acceptability of the Renyi, Tsallis and Sharma-Mittal Holographic Dark Energy Models in the f(T,B) Gravity under Hubble’s Cutoff

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 67
Author(s):  
Salim Harun Shekh ◽  
Pedro H. R. S. Moraes ◽  
Pradyumn Kumar Sahoo
Keyword(s):  
Dark Energy ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
Field Equations ◽  
Eos Parameter ◽  
Two Fluids ◽  
Gravitational Field Equations ◽  
Energy Models ◽  
Different Types ◽  
The Universe

In the present article, we investigate the physical acceptability of the spatially homogeneous and isotropic Friedmann–Lemâitre–Robertson–Walker line element filled with two fluids, with the first being pressureless matter and the second being different types of holographic dark energy. This geometric and material content is considered within the gravitational field equations of the f(T,B) (where T is the torsion scalar and the B is the boundary term) gravity in Hubble’s cut-off. The cosmological parameters, such as the Equation of State (EoS) parameter, during the cosmic evolution, are calculated. The models are stable throughout the universe expansion. The region in which the model is presented is dependent on the real parameter δ of holographic dark energies. For all δ≥4.5, the models vary from ΛCDM era to the quintessence era.

scholarly journals Bianchi type-III Tsallis holographic dark energy model in Saez–Ballester theory of gravitation

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
M. Vijaya Santhi ◽  
Y. Sobhanbabu
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Graphical Representation ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Field Equations ◽  
Om Diagnostic ◽  
Hubble Radius ◽  
Theory Of Gravitation

AbstractIn this paper, we have investigated Tsallis holographic dark energy (infrared cutoff is the Hubble radius) in homogeneous and anisotropic Bianchi type-III Universe within the framework of Saez–Ballester scalar–tensor theory of gravitation. We have constructed non-interaction and interaction dark energy models by solving the Saez–Ballester field equations. To solve the field equations, we assume a relationship between the metric potentials of the model. We developed the various cosmological parameters (namely deceleration parameter q, equation of state parameter $$\omega _t$$ ω t , squared sound speed $$v_s^2$$ v s 2 , om-diagnostic parameter Om(z) and scalar field $$\phi $$ ϕ ) and well-known cosmological planes (namely $$\omega _t-\omega _t^{'}$$ ω t - ω t ′ plane, where $$'$$ ′ denotes derivative with respect to ln(a) and statefinders ($$r-s$$ r - s ) plane) and analyzed their behavior through graphical representation for our both the models. It is also, quite interesting to mention here that the obtained results are coincide with the modern observational data.

scholarly journals Cosmology of Barrow Holographic Dark Energy as Nojiri-Odintsov Holographic Dark Energy with Specific Cut-off and the Thermodynamics

2021 ◽  
Author(s):  
Gargee Chakraborty ◽  
Surajit Chattopadhyay ◽  
Ertan Güdekli ◽  
Irina Radinschi
Keyword(s):  
Phase Transition ◽  
Dark Energy ◽  
Holographic Dark Energy ◽  
Second Law Of Thermodynamics ◽  
Electroweak Symmetry Breaking ◽  
Second Law ◽  
Late Time ◽  
Electroweak Symmetry ◽  
Eos Parameter ◽  
Reconstruction Scheme

Motivated by the work of Saridakis (Phys. Rev. D 102, 123525 (2020)), the present study reports the cosmological consequences of Barrow holographic dark energy (HDE) and its thermodynamics. Literatures demonstrate that Dark Energy (DE) may result from electroweak symmetry breaking that triggers a phase transition from early inflation to late time acceleration. In the present study, we incorporated viscosity in the Barrow HDE. A reconstruction scheme is presented for the parameters associated with Barrow holographic dark energy under the purview of viscous cosmology. Equation of state (EoS) parameter is reconstructed in this scenario and quintessence behaviour is observed. Considering BarrowHDE as a specific case ofNojiri-Odintsov (NO) HDE, we have observed quintom behaviour of the EoS parameter and for some values of n the EoS has been observed to be very close to &minus;1 for the current universe. The generalised second law of thermodynamics has come out to be valid in all the scenarios under consideration. Physical viability of considering Barrow HDE as a specific case of NO HDE is demonstrated in this study.

scholarly journals Holographic dark energy in the DGP braneworld with Granda-Oliveros cutoff

2014 ◽  
Vol 89 (12) ◽  
Author(s):  
S. Ghaffari ◽  
M. H. Dehghani ◽  
A. Sheykhi
Keyword(s):  
Dark Energy ◽  
Holographic Dark Energy ◽  
Dgp Braneworld
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