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Related papers: Can dark energy be decaying?

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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

A phenomenological model of dark energy that tracks the baryonic and cold dark matter at early times but resembles a cosmological constant at late times is explored. In the transition between these two regimes, the dark energy density drops…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-13 Jannis Bielefeld , W. L. Kimmy Wu , Robert R. Caldwell , Olivier Dore

We propose a new scenario for the onset of positive acceleration of our Universe based on symmetry breaking in coupled dark energy scalar field model. In a symmetry breaking process where the scalar field rolls down its own potential, the…

General Relativity and Quantum Cosmology · Physics 2016-10-11 H. Mohseni Sadjadi , M. Honardoost , H. R. Sepangi

We investigate the late-time evolution of the Universe within a cosmological model in which dark matter and dark energy are identified with two interacting scalar fields. Using methods of qualitative analysis of dynamical systems, we…

General Relativity and Quantum Cosmology · Physics 2021-06-14 Paulo M. Sá

The exact solution for dynamic of conform-flat space homogeneous since dynamic equation is given. Conform mode of space metric changing in Global time theory has negative energy density. Swap of energy to this mode from another ones lead to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 D. Burlankov

It is shown that in the cosmological models based on a vacuum energy decaying as a^{-2}, where a is the scale factor of the universe, the fate of the universe in regard to whether it will collapse in future or expand forever is determined…

Astrophysics · Physics 2009-10-31 Murat Özer

In this letter, it is obtained using dual role of the Ricci scalar (physical as well as geometrical role of the Ricci scalar curvature) in a natural way without any input in the theory for it. In contrast to other models, where an idea for…

Astrophysics · Physics 2007-05-23 S. K. Srivastava

We investigate the case of a homogeneous tachyon field coupled to gravity in a spatially flat Friedman-Robertson-Walker spacetime. Assuming the field evolution to be exponentially decaying with time we solve the field equations and show…

Astrophysics · Physics 2009-11-11 A. Das , Shashikant Gupta , Tarun Deep Saini , Sayan Kar

An overview is presented of a recently proposed "radically conservative" solution to the problem of dark energy in cosmology. The proposal yields a model universe which appears to be quantitatively viable, in terms of its fit to supernovae…

Astrophysics · Physics 2017-08-23 David L. Wiltshire

Theories of evolving quintessence are constructed that generically lead to deviations from the w = -1 prediction of non-evolving dark energy. The small mass scale that governs evolution, m_\phi \approx 10^{-33} eV, is radiatively stable,…

Astrophysics · Physics 2009-09-29 Lawrence J. Hall , Yasunori Nomura , Steven J. Oliver

We suggest a scalar model of dark energy with the SO(1,1) symmetry. The model may be reformulated in terms of a real scalar field $\Phi$ and the scale factor $a$ so that the Lagrangian may be decomposed as that of the real quintessence…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Yi-Huan Wei , Yu Tian

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 2007-05-23 J. Besprosvany

It is described dynamics of a large class of accelerating cosmological models in terms of dynamical systems of the Newtonian type. The evolution of the models is reduced to the motion of a particle in a potential well parameterized by the…

Astrophysics · Physics 2017-09-29 Marek Szydlowski , Aleksandra Kurek

We study cosmological effects of homogeneous tachyon field as dark energy. We concentrate on two different scalar field potentials, the inverse square potential and the exponential potential. These models have a unique feature that the…

Astrophysics · Physics 2008-11-26 H. K. Jassal

Simple models are constructed for "acceleressence" dark energy: the latent heat of a phase transition occurring in a hidden sector governed by the seesaw mass scale v^2/M_Pl, where v is the electroweak scale and M_Pl the gravitational mass…

Astrophysics · Physics 2009-09-29 Z. Chacko , Lawrence J. Hall , Yasunori Nomura

We consider the oscillating dark energy with periodic equation of state in two equivalent formulations: ideal fluid or scalar-tensor theory. It is shown that such dark energy suggests the natural way for the unification of early-time…

High Energy Physics - Theory · Physics 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov

Dark energy is one of the mysteries of modern science. It is unlike any known form of matter or energy and has been detected so far only by its gravitational effect of repulsion. Owing to its effects being discernible only at very very…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-25 Aruna Kesavan

We consider a cosmology with decaying metastable dark energy and assume that a decay process of this metastable dark energy is a quantum decay process. Such an assumption implies among others that the evolution of the Universe is…

General Relativity and Quantum Cosmology · Physics 2019-09-27 Aleksander Stachowski , Marek Szydlowski , Krzysztof Urbanowski

In this paper, basics and some theoretical models of dark energy are reviewed. Theoretical models include cosmological constant, vacuum fluctuations of quantum fields, scalar field models, chaplygin gas, vector field models and Brane world…

General Relativity and Quantum Cosmology · Physics 2009-10-29 R. Rakhi , K. Indulekha

Current cosmological data indicate that our universe contains a substantial component of dark vacuum energy that is driving the cosmos to accelerate. We examine the immediate and longer term consequences of this dark energy (assumed here to…

Astrophysics · Physics 2010-12-09 Michael T. Busha , Fred C. Adams , Risa H. Wechsler , August E. Evrard