Bound on the Equation of State of Dark Energy from the Generalized Second Law of Thermodynamics

2011 ◽  
Vol 51 (6) ◽  
pp. 1692-1697 ◽  
Author(s):  
Rong-Jia Yang ◽  
Jing-Zhao Qi ◽  
Lihua Feng
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Generalized Second Law

The barrow holographic dark energy-based reconstruction of f(R) gravity and cosmology with Nojiri–Odintsov cutoff

2021 ◽  
pp. 2150148
Author(s):  
Amrita Sarkar ◽  
Surajit Chattopadhyay
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Holographic Dark Energy ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Transition Model ◽  
Late Time ◽  
Reconstruction Scheme ◽  
Generalized Second Law ◽  
Special Case

In the work reported here we have considered Barrow holographic dark energy (BHDE) proposed in E. N. Saridakis, Barrow holographic dark energy, Phys. Rev. D 102 (2020) 123525 as a special case of more generalized version of Nojiri–Odintsov holographic dark energy (NOHDE) proposed in S. I. Nojiri and S. D. Odintsov, Unifying phantom inflation with late-time acceleration: Scalar phantom–non-phantom transition model and generalized holographic dark energy, Gen. Relativ. Gravit. 38 (2006) 1285–1304 and also reconstructed [Formula: see text] gravity with BHDE as the form of background evolution. It has been observed that in the case of BHDE reconstructed [Formula: see text] gravity the equation of state can have a transition from quintessence to phantom. In a particular case of reconstruction, possibility of Little Rip singularity has been observed. Finally, the generalized second law of thermodynamics has been found to be valid under this reconstruction scheme.

Cosmological consequences of modified Friedmann equations according to holographic equipartition law

2021 ◽  
Vol 36 (10) ◽  
pp. 2150069
Author(s):  
Abdul Jawad ◽  
Sidra Saleem ◽  
Saba Qummer
Keyword(s):  
Equation Of State ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Om Diagnostic ◽  
Generalized Second Law ◽  
Friedmann Equations ◽  
Equation Of State Parameter ◽  
Equipartition Law

We examine thermodynamically an extra driving term for the flat universe by applying Sharma Mittal entropy to Padmanabhan’s holographic equipartition law. Deviations from the Bekenstein–Hawking entropy by using this law, we generate an extra driving in the acceleration equation. By using the constant and parametrized equation of state parameter, we investigate the different cosmological parameters like deceleration parameter, squared speed of sound, Om-diagnostic and statefinder parameter through graphical approach. We observe compatible results with current observational data in both models. Generalized second law of thermodynamics also remains valid in both cases.

scholarly journals VISCOUS DARK ENERGY AND GENERALIZED SECOND LAW OF THERMODYNAMICS

2010 ◽  
Vol 19 (07) ◽  
pp. 1205-1215 ◽  
Author(s):  
M. R. SETARE ◽  
A. SHEYKHI
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Time Evolution ◽  
Casimir Effect ◽  
Apparent Horizon ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Total Entropy ◽  
Generalized Second Law ◽  
The Universe

We examine the validity of the generalized second law of thermodynamics in a non-flat universe in the presence of viscous dark energy. First we assume that the universe is filled only with viscous dark energy. Then, we extend our study to the case where there is an interaction between viscous dark energy and pressureless dark matter. We examine the time evolution of the total entropy, including the entropy associated with the apparent horizon and the entropy of the viscous dark energy inside the apparent horizon. Our study shows that the generalized second law of thermodynamics is always protected in a universe filled with interacting viscous dark energy and dark matter in a region enclosed by the apparent horizon. Finally, we show that the the generalized second law of thermodynamics is fulfilled for a universe filled with interacting viscous dark energy and dark matter by taking into account the Casimir effect.

scholarly journals THERMODYNAMICS IN KALUZA–KLEIN UNIVERSE

2013 ◽  
Vol 28 (17) ◽  
pp. 1350072 ◽  
Author(s):  
M. SHARIF ◽  
RABIA SALEEM
Keyword(s):  
Dark Energy ◽  
Apparent Horizon ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Model Parameters ◽  
Ricci Dark Energy ◽  
Generalized Second Law ◽  
Energy Models ◽  
Fixed Radius ◽  
Kaluza Klein

This paper is devoted to check the validity of laws of thermodynamics for Kaluza–Klein universe in the state of thermal equilibrium, composed of dark matter and dark energy. The generalized holographic dark energy and generalized Ricci dark energy models are considered here. It is proved that the first and generalized second law of thermodynamics are valid on the apparent horizon for both of these models. Further, we take a horizon of radius L with modified holographic or Ricci dark energy. We conclude that these models do not obey the first and generalized second law of thermodynamics on the horizon of fixed radius L for a specific range of model parameters.

Thermodynamics of specific modified gravity with generalized interaction term

2018 ◽  
Vol 15 (03) ◽  
pp. 1850033
Author(s):  
Abdul Jawad ◽  
Shamaila Rani ◽  
Tanzeela Nawaz
Keyword(s):  
Dark Energy ◽  
Modified Gravity ◽  
Holographic Dark Energy ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Generalized Second Law ◽  
Energy Models ◽  
Interaction Term ◽  
Hubble Horizon ◽  
Chern Simons

We investigate the generalized second law of thermodynamics by assuming the interaction of dark energy and dark matter in Chern–Simons modified gravity. We consider a family of holographic dark energy models by assuming its various cutoffs such as Hubble horizon, event horizon, their combination, Ricci scalar and its generalized form. The general criteria of generalized second law of thermodynamics in terms of coincidence parameter is being developed. This criterion is being applied for the above-mentioned holographic dark energy models to check the validity of the generalized second law of thermodynamics and the constraints where it is respected are referred.

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