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Related papers: Dark Energy and Search for the Generalized Second …

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We investigate the validity of generalized second law of thermodynamics of a physical system comprising of newly proposed dark energy model called Ricci Gauss-Bonnet and cold dark matter enveloped by apparent horizon and event horizon in…

General Relativity and Quantum Cosmology · Physics 2018-03-12 Ayesha Iqbal , Abdul Jawad

This work is focused on the exploration of the thermodynamics foundations of the matter creation scenario when a generalized form of the second law of thermodynamics for this scheme is implemented. In this scenario we consider an expanding…

General Relativity and Quantum Cosmology · Physics 2024-07-23 Víctor H. Cárdenas , Miguel Cruz , Samuel Lepe

We review the main features of the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and discuss how it admits an unique decomposition into dark energy and dark matter components once phantom-like dark…

Astrophysics · Physics 2017-08-23 Orfeu Bertolami

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

Observations provide increasingly strong evidence that the universe is accelerating. This revolutionary advance in cosmological observations confronts theoretical cosmology with a tremendous challenge, which it has so far failed to meet.…

Astrophysics · Physics 2008-11-26 Ruth Durrer , Roy Maartens

The expansion of the Universe is accelerating, as testified by observations of supernovae of type Ia as a function of redshift. Explanations are of two types: modifications of Einstein gravity or new forms of energy, coined dark energy.The…

Astrophysics · Physics 2007-05-23 Matts Roos

We examine the validity of the generalized second law of thermodynamics in a non-flat universe in the presence of viscous dark energy. At first we assume that the universe filled only with viscous dark energy. Then, we extend our study to…

General Physics · Physics 2011-03-15 M. R. Setare , A. Sheykhi

In this paper we have considered the holographic dark energy and studied it's cosmology and thermodynamics. We have analysed the generalized second law (GSL) of thermodynamics in a flat universe consists of interacting dark energy and dark…

General Relativity and Quantum Cosmology · Physics 2014-02-03 Praseetha P. , Titus K. Mathew

In this letter, we investigate the validity of the generalized second law of thermodynamics of the universe bounded by the event horizon in the holographic dark energy model. The universe is chosen to be homogeneous and isotropic and the…

General Relativity and Quantum Cosmology · Physics 2010-11-04 Nairwita Mazumder , Subenoy Chakraborty

Despite the interest in dark matter and dark energy, it has never been shown that they are in fact two separate substances. We provide the first strong evidence that they are separate by ruling out a broad class of so-called unified dark…

Astrophysics · Physics 2008-11-26 Havard Sandvik , Max Tegmark , Matias Zaldarriaga , Ioav Waga

We have investigated the thermodynamical properties of the Universe with dark energy. Adopting the usual assumption in deriving the constant co-moving entropy density that the physical volume and the temperature are independent, we observed…

General Relativity and Quantum Cosmology · Physics 2010-10-27 Yungui Gong , Bin Wang , Anzhong Wang

We investigate the validity of the generalized second law of gravitational thermodynamics on the apparent and event horizons in a non-flat FRW universe containing the interacting dark energy with dark matter. We show that for the dynamical…

General Relativity and Quantum Cosmology · Physics 2011-01-18 K. Karami , S. Ghaffari , M. M. Soltanzadeh

In this work the collapsing process of a spherically symmetric star, made of dust cloud, in the background of dark energy is studied for two different gravity theories separately, i.e., DGP Brane gravity and Loop Quantum gravity. Two types…

General Physics · Physics 2015-06-04 Prabir Rudra , Ritabrata Biswas , Ujjal Debnath

It has been only ~15 years since the discovery of dark energy (although some may argue there were strong indications even earlier). In the short time since measurements of type Ia supernovae indicated an accelerating universe, many other…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Tamara M. Davis

We consider the generalized Chaplygin gas (GCG) proposal for unification of dark energy and dark matter and show that it admits an unique decomposition into dark energy and dark matter components once phantom-like dark energy is excluded.…

Astrophysics · Physics 2009-10-29 M. C. Bento , O. Bertolami , A. A. Sen

In this paper we will investigate the validity of the Generalized Second Law of thermodynamics for the Quintom model of dark energy. Reviewing briefly the quintom scenario of dark energy, we will study the conditions of validity of the…

High Energy Physics - Theory · Physics 2009-11-11 M R Setare

A new model describing the dark sector of the universe is established. The model involves Bose-Einstein condensate (BEC) as dark energy (DE) and an excited state above it as dark matter (DM). The condensate is assumed to have a negative…

General Relativity and Quantum Cosmology · Physics 2011-05-24 V. A. Popov

Recent cosmological and astrophysical observations point out that the Universe is in accelerating expansion and filled up with non-luminous matter. In order to explain the observed large scale structures and this accelerating behavior one…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-23 S. Capozziello , G. Lambiase

It is a puzzle why the densities of dark matter and dark energy are nearly equal today when they scale so differently during the expansion of the universe. This conundrum may be solved if there is a coupling between the two dark sectors. In…

High Energy Physics - Phenomenology · Physics 2009-07-09 D. Comelli , M. Pietroni , A. Riotto

The vacuum is filled with complex scalar fields, such as the Higgs field. These fields serve as order parameters for superfluidity (quantum phase coherence over macroscopic distances), making the entire universe a superfluid. We review a…

General Relativity and Quantum Cosmology · Physics 2013-11-18 Kerson Huang