English
Related papers

Related papers: On Phantom Thermodynamics

200 papers

Considering an arbitrary, varying equation of the state parameter, the thermodynamic properties of the dark energy fluid in a semiclassical loop quantum cosmology scenario, which we consider the inverse volume modification, is studied. The…

General Relativity and Quantum Cosmology · Physics 2011-03-22 Kui Xiao , Jian-Yang Zhu

In the standard cosmological framework of the 0th-order FLRW metric and the use of perfect fluids in the stress-energy tensor, dark energy with an equation-of-state parameter $w < -1$ (known as phantom dark energy) implies negative kinetic…

General Physics · Physics 2018-09-12 Kevin J. Ludwick

In this work, we study some thermodynamical aspects associated with torsion in a flat FLRW spacetime cosmic evolution. By implementing two Ansatze for the torsion term, we find that the model admits a phantom regime or a quintessence…

General Relativity and Quantum Cosmology · Physics 2020-06-26 Miguel Cruz , Fernando Izaurieta , Samuel Lepe

Do negative absolute temperatures matter physics and specifically Statistical Physics? We provide evidence that we can certainly answer positively to this vexata quaestio. The great majority of models investigated by statistical mechanics…

Statistical Mechanics · Physics 2021-07-07 Marco Baldovin , Stefano Iubini , Roberto Livi , Angelo Vulpiani

It has been suggested that a possible candidate for the present accelerated expansion of the Universe is ''phantom energy''. The latter possesses an equation of state of the form $\omega\equiv p/\rho<-1$, consequently violating the null…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Francisco S. N. Lobo

We derive the dark energy fluid equation of state $P = -\epsilon = {\rm const.}$ as an extremum of entropy, subject to the Hamiltonian constraint of General Relativity. However, we identify perturbations that can render this extremum an…

General Relativity and Quantum Cosmology · Physics 2023-02-09 Zacharias Roupas

Holographic dark energy models have been recently suggested which most clearly show that accelerating cosmology appears to be incompatible with mathematically consistent formulations of fundamental theories such as string/M theories. In…

Astrophysics · Physics 2007-05-23 Pedro F. Gonzalez-Diaz

We consider a substance with equation of state $P=wE$ at constant $w$ and find that it is an ideal gas of quasi-particles with the energy spectrum $\epsilon_p\sim p^{wq}$ that can constitute either regular matter (when $w>0$) or exotic…

Statistical Mechanics · Physics 2011-08-08 Ernst Trojan , George V. Vlasov

Thermodynamic properties of dark energy are discussed assuming that dark energy is described in terms of a selfinteracting complex scalar. We first show that, under certain assumptions, selfinteracting complex scalar field theories are…

General Relativity and Quantum Cosmology · Physics 2010-09-28 Neven Bilic

In the present work, we have made an attempt to investigate the dark energy possibility from the thermodynamical point of view. For this purpose, we have studied thermodynamic stability of three popular dark energy models in the framework…

General Relativity and Quantum Cosmology · Physics 2021-01-18 Abdulla Al Mamon , Pritikana Bhandari , Subenoy Chakraborty

We investigate a generalized power-law dark energy equation of state of the form $p = w\rho - \beta\rho^m$ in a flat FLRW universe, analyzing its dynamical stability and thermodynamic consistency. The model exhibits a rich phase space…

General Relativity and Quantum Cosmology · Physics 2025-07-08 S. Kazemi , M. A. Ramzanpour , E. Yusofi , A. R. Amani

The effects of low dimensionality on the thermodynamics of a Fermi gas trapped by isotropic power law potentials are analyzed. Particular attention is given to different characteristic temperatures that emerge, at low dimensionality, in the…

Quantum Gases · Physics 2017-01-31 Francisco J. Sevilla

We investigate the restrictions on the equation-of-state parameter of phantom cosmology, due to the minimum quantum gravitational requirements. We find that for all the examined $w_\Lambda(z)$-parametrizations and for arbitrary phantom…

High Energy Physics - Theory · Physics 2014-11-18 Emmanuel N. Saridakis

In this work we explore some cosmological properties coming from the particle and future horizons when are considered as candidates to model the dark energy sector within a holographic context in a flat Friedmann-Lemaitre-Robertson-Walker…

General Relativity and Quantum Cosmology · Physics 2020-04-29 Miguel Cruz , Samuel Lepe

A significant observational effort has been directed to unveil the nature of the so-called dark energy. However, given the large number of theoretical possibilities, it is possible that such a task cannot be performed on the basis only of…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-12 R. Silva , R. S. Goncalves , J. S. Alcaniz , H. H. B. Silva

Recent determinations of the equation of state of dark energy hint that this may well be of the phantom type, i.e., $w_{de} < -1$. If confirmed by future experiments, this would strongly point to the existence of fields that violate the…

General Relativity and Quantum Cosmology · Physics 2015-06-24 Rafael C. Nunes , Diego Pavón

A possible candidate for the present accelerated expansion of the Universe is ''phantom energy'', which possesses an equation of state of the form $\omega\equiv p/\rho<-1$, consequently violating the null energy condition. As this is the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Francisco S. N. Lobo

Equation of state parameter plays a significant role for guessing the real nature of dark energy. In the present paper polytropic equation of state $p=\omega\rho^n$ is chosen for some of the kinematical $\Lambda$-models viz., $\Lambda \sim…

Astrophysics · Physics 2009-02-11 Utpal Mukhopadhyay , Saibal Ray

The thermodynamical properties of dark energy are usually investigated with the equation of state $\omega =\omega_{0}+\omega_{1}z$. Recent observations show that our universe is accelerating, and the apparent horizon and the event horizon…

Astrophysics · Physics 2008-11-26 Yongping Zhang , Ze-Long Yi , Tong-Jie Zhang , Wenbiao Liu

We have investigated a cosmological model of a phantom energy with a variable cosmological constant ($\Lambda$) depending on the energy density ($\rho$) as $\Lambda\propto \rho^{-\alpha}$, $\alpha=\rm const.$ and a variable gravitational…

High Energy Physics - Theory · Physics 2008-12-25 Arbab I. Arbab