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Related papers: Thermodynamics of a transient phantom scenario

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A thermodynamic description of cosmological spacetimes may provide insights into the fundamentals of the cosmic evolution that remain otherwise obscure, similar to `black hole thermodynamics'. We investigate the thermodynamic properties of…

General Relativity and Quantum Cosmology · Physics 2026-03-31 Dipayan Mukherjee , Harkirat Singh Sahota , Swati Gavas

We show that, in general, any complex weakly nonlinear highly multimode system can reach thermodynamic equilibrium that is characterized by a unique temperature and chemical potential. The conditions leading to either positive or negative…

At low temperature a thermodynamic system undergoes a phase transition when a physical parameter passes through a singularity point of the free energy, corresponding to formation of a new order. At high temperature the thermal fluctuations…

Statistical Mechanics · Physics 2014-06-17 Bo-Bo Wei , Shao-Wen Chen , Hoi-Chun Po , Ren-Bao Liu

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

We describe the quasi-static collapse of a radiating, spherical shell of matter in de Sitter space-time using a thermodynamical formalism. It is found that the specific heat at constant area and other thermodynamical quantities exhibit…

General Relativity and Quantum Cosmology · Physics 2008-11-26 G. L. Alberghi , R. Casadio , G. Venturi

We consider the thermodynamic potential describing the macroscopic fluctuation of the current and local energy of a general class of Hamiltonian models including aerogels. We argue that this potential is neither analytic nor strictly…

Mathematical Physics · Physics 2015-05-19 Raphael Lefevere , Mauro Mariani , Lorenzo Zambotti

We present a conjugate analysis of two different dark energy models investigating both their agreement with recent data and their thermodynamical properties. The successful match with the data allows to both constrain the model parameters…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-11 Vincenzo F. Cardone , Ninfa Radicella , Antonio Troisi

In this work, we study tracker phantom dark energy models with a general parameterization of the scalar potentials. Our analysis also considers the scenario of having both phantom field and the cosmological constant as the dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-18 Francisco X. Linares Cedeño , Nandan Roy , L. Arturo Ureña-López

In the context of thermodynamics we discuss the way inevitable emerge an interaction between dark components, and in this way, provide a mechanism to understand the limits of the LCDM model and the class of interaction models between dark…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-22 Víctor H. Cárdenas , Daniela Grandón , Samuel Lepe

Recently, the observed equation of state for dark energy appears to favor values below $-1$. The tendency implies that the nature of dark energy may be quite different from that of the cosmological constant. In view of the adjustment on the…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-13 Yu-Ping Teng , Wolung Lee , Kin-Wang Ng

Phantom energy which violates the dominant-energy condition and is not excluded by current constraints on the equation of state may be dominating the evolution of the universe now. It has been pointed out that in such a case the fate of the…

Astrophysics · Physics 2009-11-07 Pedro F. Gonzalez-Diaz

Thermodynamics could be seen as an expression of physics at a high epistemic level. As such, its potential as an inductive bias to help machine learning procedures attain accurate and credible predictions has been recently realized in many…

Machine Learning · Computer Science 2023-05-29 Elias Cueto , Francisco Chinesta

It is well known that, in the context of general relativity, an unknown kind of matter that must violate the strong energy condition is required to explain the current accelerated phase of expansion of the Universe. This unknown component…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-22 Ronaldo C. Duarte , Edésio M. Barboza , Everton M. C. Abreu , Jorge Ananias Neto

The consideration of dark energy's quanta, required also by thermodynamics, introduces its chemical potential into the cosmological equations. Isolating its main contribution, we obtain solutions with dark energy decaying to matter or…

Astrophysics · Physics 2008-11-26 J. Besprosvany

We investigate, in a unified and general way, the thermodynamic properties of dark energy with an arbitrary, varying equation-of-state parameter w(a). We find that all quantities are well defined and regular for every w(a), including at the…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-05 Emmanuel N. Saridakis , Pedro F. Gonzalez-Diaz , Carmen L. Siguenza

The dark energy crossing of the cosmological constant boundary (the transition between the quintessence and phantom regimes) is described in terms of the implicitly defined dark energy equation of state. The generalizations of the models…

Astrophysics · Physics 2009-11-13 Hrvoje Stefancic

The theory of false vacuum decay in a thermal system may have a cross-over from predominantly thermal transitions to quantum transitions as the temperature is decreased. New numerical methods and results are presented here that can be used…

High Energy Physics - Theory · Physics 2023-03-01 Mario Gutierrez Abed , Ian G. Moss

Dark energy away from a cosmological constant $\Lambda$ -- like early universe inflation that ends -- can be understood in terms of well defined physical behaviors. These guide dark energy into thawing or freezing classes, with $w_0$--$w_a$…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-16 Eric V. Linder

We describe the thermodynamical interpretation of the interaction between new agegraphic dark energy and dark matter in a non-flat universe. When new agegraphic dark energy and dark matter evolve separately, each of them remains in…

General Relativity and Quantum Cosmology · Physics 2011-09-05 A. Sheykhi , M. R. Setare

We consider a higher dimensional gravity theory with a negative kinetic energy scalar field and a cosmological constant. We find that the theory admits an exact cosmological solution for the scale factor of our universe. It has the feature…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. T. Hong , J. Lee , T. H. Lee , P. OH