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Related papers: Dark energy from Geometrothermodynamics

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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

This contribution intends to give a pedagogical introduction to the topic of dark energy (the mysterious agent supposed to drive the observed late time acceleration of the Universe) and to various observational tests which require only…

Astrophysics · Physics 2008-11-26 Ruth Lazkoz

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

To explain the acceleration of the cosmological expansion researchers have considered an unusual form of mass-energy generically called dark energy. Dark energy has a ratio of pressure over mass density which obeys $w=p/\rho <-1/3$. This…

High Energy Physics - Theory · Physics 2008-12-19 Max Chaves , Douglas Singleton

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

In this paper, we interpret the dark energy phenomenon as an averaged effect caused by small scale inhomogeneities of the universe with the use of the spatial averaged approach of Buchert. Two models are considered here, one of which…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-19 YanHong Yao , Xin-He Meng

We investigate the interaction between dark energy and dark matter in the framework of irreversible thermodynamics of open systems with matter creation/annihilation. We consider dark energy and dark matter as an interacting two component…

General Relativity and Quantum Cosmology · Physics 2013-02-08 Tiberiu Harko , Francisco S. N. Lobo

The physical process leading to the acceleration of the expansion of the universe is unknown. It may involve new high energy physics or extensions to gravitation. Calling this generically dark energy, we examine the consistencies and…

Astrophysics · Physics 2009-11-10 Eric V. Linder

In order to explain the Late-times accelerated expansion of the Universe we must appeal to some form of Dark Energy. In the standard model of cosmology, the latter is interpreted as a Cosmological Constant $\Lambda$. However, for a number…

General Relativity and Quantum Cosmology · Physics 2021-02-18 Leonardo Giani

In this paper, we point out thermodynamical description of ghost dark energy and its generalization to the early universe. Thereinafter, we find expressions for the entropy changes of these dark energy candidates. In addition, considering…

General Relativity and Quantum Cosmology · Physics 2015-05-06 M. Honarvaryan , A. Sheykhi , H. Moradpour

A long-standing topic of interest in the general theory of relativity is the embedding of curved spacetimes in higher-dimensional flat spacetimes. The main purpose this paper is to show that the embedding theory can account for the…

General Relativity and Quantum Cosmology · Physics 2021-06-11 Peter K. F. Kuhfittig , Vance D. Gladney

Following the holographic principle, which suggests that the energy density of dark energy may be proportional inversely to the area of the event horizon of the Universe, we have proposed a new energy density of dark energy through the…

General Relativity and Quantum Cosmology · Physics 2023-01-25 H. R. Fazlollahi

It is shown that so-called dark energy could possible be a manifestation of the gravitational vortex producing the "gravitomagnetic" (GM) force field: associated with cosmic matter rotation and inertial spacetime frame dragging. The general…

General Physics · Physics 2018-01-24 Reva Kay Williams

The expansion rate of the Universe changes with time, initially slowing (decelerating) when the universe was matter dominated, because of the mutual gravitational attraction of all the matter in it, and more recently speeding up…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-17 Muhammad Omer Farooq

We study the bending of light for static spherically symmetric (SSS) space-times which include a dark energy contribution. Geometric dark energy models generically predict a correction to the Einstein angle written in terms of the distance…

Astrophysics · Physics 2008-11-26 Fabio Finelli , Matteo Galaverni , Alessandro Gruppuso

In the $\Lambda$CDM model, dark energy is viewed as a constant vacuum energy density, the cosmological constant in the Einstein--Hilbert action. This assumption can be relaxed in various models that introduce a dynamical dark energy. In…

High Energy Physics - Theory · Physics 2020-11-19 Vishnu Jejjala , Michael J. Kavic , Djordje Minic , Tatsu Takeuchi

In the timescape scenario cosmic acceleration is understand as an apparent effect, due to gravitational energy gradients that grow when spatial curvature gradients become significant with the nonlinear growth of cosmic structure. This…

Cosmology and Nongalactic Astrophysics · Physics 2010-07-14 David L. Wiltshire

The accelerated expansion of the Universe is one of the main discoveries of the past decades, indicating the presence of an unknown component: the dark energy. Evidence of its presence is being gathered by a succession of observational…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-13 V. Motta , Miguel A. García-Aspeitia , A. Hernández-Almada , J. Magaña , Tomás Verdugo

The cosmographic technique is a powerful model-independent tool for distinguishing between competing cosmological scenarios. The key strengths and weaknesses of standard cosmography are discussed in view of healing the convergence problem…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-01 Salvatore Capozziello , Rocco D'Agostino

The late time acceleration of the Universe has challenged contemporary cosmology since its discovery. General Relativity explains this phenomenon by introducing the cosmological constant, named the standard cosmological model…

General Relativity and Quantum Cosmology · Physics 2024-01-02 Simran Arora