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Related papers: Cosmological Equations for Interacting Energies

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We explore the possibility of having a composite (self-conserved) dark energy (DE) whose dynamics is controlled by the quantum running of the cosmological parameters. We find that within this scenario it is feasible to find an explanation…

Astrophysics · Physics 2009-11-11 Javier Grande , Joan Sola , Hrvoje Stefancic

A so-called "agegraphic dark energy" was recently proposed to explain the dark energy-dominated universe. In this Letter, we generalize the agegraphic dark energy models to the universe with spatial curvature in the presence of interaction…

High Energy Physics - Theory · Physics 2009-10-16 Ahmad Sheykhi

Vacuum energy is a simple model for dark energy driving an accelerated expansion of the universe. If the vacuum energy is inhomogeneous in spacetime then it must be interacting. We present the general equations for a spacetime-dependent…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-01 Josue De-Santiago , David Wands , Yuting Wang

A cosmological model with pressurelless matter and a fluid of negative pressure is studied. At perturbative level, fluctuations of both fluids are considered. It is shown that at least at very large scales, the fluid of negative pressure,…

Astrophysics · Physics 2009-11-07 F. G. Alvarenga , J. C. Fabris , S. V. B. Gonçalves , G. Tadaiesky

The standard model of cosmology is investigated using time dependent cosmological constant $\Lambda$ and Newton's gravitational constant $G$. The total energy content is described by the modified Chaplygin gas equation of state. It is found…

General Relativity and Quantum Cosmology · Physics 2009-03-12 Mubasher Jamil , Farook Rahaman , Mehedi Kalam

We extend the cosmological couplings proposed in Sun et al. and Wei, where they suggested interactions with change of signs along the cosmological evolution. Our extension liberates the changes of sign of the interaction from the…

General Relativity and Quantum Cosmology · Physics 2014-09-25 Mónica Forte

A non-minimal coupling between the dark matter and dark energy components may offer a way of solving the so-called coincidence problem. In this paper we propose a low-$z$ test for such hypothesis using measurements of the gas mass fraction…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-09 R. S. Goncalves , G. C. Carvalho , J. S. Alcaniz

Models involving an interaction between the Dark Matter and the Dark Energy sectors have been proposed to alleviate the long standing Hubble constant tension. In this paper we analyze whether the constraints and potential hints obtained for…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-11 Eleonora Di Valentino , Olga Mena

In this paper is proposed a geometric solution to the dark energy, assuming that the space can be divided into regions of size $\sim L_{p}$ and energy $\sim E_{p}$. Significantly this assumption generate a energy density similar to the…

General Relativity and Quantum Cosmology · Physics 2011-02-08 Miguel Angel García-Aspeitia

The standard model of cosmology suggests the existence of two components, "dark matter" and "dark energy", which determine the fate of the Universe. Their nature is still under investigation, and no direct proof of their existences has…

Astrophysics · Physics 2009-07-09 A. Arbey

A recently proposed Dynamical Space-time Cosmology (DSC) that unifies dark energy and dark matter is studied. The general action of this scenario includes a Lagrange multiplier, which is coupled to the energy momentum tensor and a scalar…

General Relativity and Quantum Cosmology · Physics 2019-06-10 Fotios K. Anagnostopoulos , David Benisty , Spyros Basilakos , Eduardo I. Guendelman

In this work we study in detail a phenomenological generalization of the Chaplygin cosmological model, which we call as \textit{umami} Chaplygin model. We consider three different cosmological background scenarios in which our fluid can…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-04 Ruth Lazkoz , María Ortiz-Baños , Vincenzo Salzano

The Universe is modeled as a binary mixture whose constituents are described by a van der Waals fluid and by a dark energy density. The dark energy density is considered either as the quintessence or as the Chaplygin gas. The irreversible…

General Relativity and Quantum Cosmology · Physics 2009-11-10 G. M. Kremer

In the contemporary Cosmology, dark energy is modeled as a perfect fluid, having a very simple equation of state: pressure is proportional to dark energy density. As an alternative, I propose a more complex equation of state, with pressure…

General Physics · Physics 2009-11-04 Dragan Slavkov Hajdukovic

Interactions inside the cosmological dark sector influence the cosmological dynamics. As a consequence, the future evolution of the Universe may be different from that predicted by the $\Lambda$CDM model. We review main features of several…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-30 W. Zimdahl

Diverse cosmological and astrophysical observations strongly hint at the presence of dark matter and dark energy in the Universe. One of the main goals of Cosmology is to explain the nature of these two components. It may well be that both…

High Energy Physics - Theory · Physics 2023-07-10 Carsten van de Bruck , Gaspard Poulot , Elsa M. Teixeira

Despite our present-day inability to predict the topology of the universe it is expected that we should be able to detect it in the near future. A nontrivial detectable topology of the space section of the universe can be probed for all…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-04 M. J. Reboucas , A. F. F. Teixeira

The fact that the energy densities of dark energy and matter are similar currently, known as the coincidence problem, is one of the main unsolved problems of cosmology. We present here a model in which a spatial curvature of the universe…

Astrophysics · Physics 2009-11-13 Urbano Franca

A huge amount of good quality data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision Cosmology. Despite…

General Relativity and Quantum Cosmology · Physics 2008-12-02 S. Capozziello

In this study, we will look at an interacting dark energy model. In the framework of Friedmann-Robertson-Walker (FRW) space-time, we have made the hypothesis of an interacting scheme between two fields (dark matter (DM) and dark energy…

General Relativity and Quantum Cosmology · Physics 2023-11-27 J. K. Singh , Ritika Nagpal