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We investigate the effects of homogeneous general dark energy on the non-linear matter perturbation in fully general relativistic context. The equation for the density contrast contains even at linear order new contributions which are…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-30 Sang Gyu Biern , Jinn-Ouk Gong

Dynamic dark energy (DDE) models are often designed to solve the cosmic coincidence (why, just now, is the dark energy density $\rho_{de}$, the same order of magnitude as the matter density $\rho_m$?) by guaranteeing $\rho_{de} \sim \rho_m$…

Astrophysics · Physics 2008-11-26 Chas A. Egan , Charles H. Lineweaver

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

I consider some of the issues we face in trying to understand dark energy. Huge fluctuations in the unknown dark energy equation of state can be hidden in distance data, so I argue that model-independent tests which signal if the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Chris Clarkson

We generalize the small scale dynamics of the universe by taking into account models with an equation of state which evolves with time, and provide a complete formulation of the cluster virialization attempting to address the nonlinear…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-01 S. Basilakos , J. C. Bueno Sanchez , Leandros Perivolaropoulos

While there is plentiful evidence in all fronts of experimental cosmology for the existence of a non-vanishing dark energy (DE) density \rho_D in the Universe, we are still far away from having a fundamental understanding of its ultimate…

Astrophysics · Physics 2011-07-19 Javier Grande , Ana Pelinson , Joan Sola

In this article, we review a series of recent theoretical results regarding a conventional approach to the dark energy (DE) concept. This approach is distinguished among others for its simplicity and its physical relevance. By compromising…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-20 Kostas Kleidis , Nikolaos K. Spyrou

We find that if we live at the center of an inhomogeneity with total density contrast of roughly 0.1, dark energy is not a cosmological constant at 95% confidence level. Observational constraints on the equation of state of dark energy, w,…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-17 Valerio Marra , Mikko Pääkkönen , Wessel Valkenburg

We introduce the Abnormally Weighting Energy (AWE) hypothesis in which dark energy (DE) is presented as a consequence of the violation of the weak equivalence principle (WEP) at cosmological scales by some dark sector. Indeed, this implies…

General Relativity and Quantum Cosmology · Physics 2016-11-15 A. Fuzfa , J. -M. Alimi

The amount and nature of dark energy (DE) can be tightly constrained by measuring the spatial correlation features and evolution of a sample of ~ 100,000 galaxy clusters over the redshift range 0<z < 1.5. Such an X-ray survey will discover…

Since the discovery of the accelerated expansion of the Universe, the constraints on the equation of state $w_\text{DE}$ of dark energy, the stress-energy component responsible for the acceleration, have tightened significantly. These…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-09 Fabian Schmidt

The distribution of dark energy density in the vicinity of compact static objects is analyzed. Dark energy is assumed to be in the form of a scalar field with three parameters: the background density, the equation of state parameter and the…

General Relativity and Quantum Cosmology · Physics 2020-08-04 M. Tsizh , B. Novosyadlyj , Yu. Kulinich

Observational evidence of dark energy that makes the Universe nearly flat at the present epoch is very strong. We study the link between spatial continuity and dark energy. We assume that comoving space is a compact 3-manifold of constant…

Cosmology and Nongalactic Astrophysics · Physics 2009-12-02 Boudewijn F. Roukema , Vincent Blanloeil

According to a generalization of black hole thermodynamics to a cosmological framework, it is possible to define a temperature for the cosmological horizon. The hypothesis of thermal equilibrium between the dark energy and the horizon has…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-02 Vincent Poitras

We study the Universe at the late stage of its evolution and deep inside the cell of uniformity. At such a scale the Universe is highly inhomogeneous and filled with discretely distributed inhomogeneities in the form of galaxies and groups…

General Relativity and Quantum Cosmology · Physics 2016-08-25 Mariam Bouhmadi-López , João Morais , Alexander Zhuk

The introduction of an interaction for dark energy to the standard cosmology offers a potential solution to the cosmic coincidence problem. We examine the conditions on the dark energy density that must be satisfied for this scenario to be…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Micheal S. Berger , Hamed Shojaei

Dark Energy not only has background effects through its equation of state $w_{DE}$, but also it can cluster through its sound speed $c^2_{sDE}$, subject to certain conditions. As is well-known, for dynamical dark energy models, dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-26 Archita Bhattacharyya , Supratik Pal

The Abnormally Weighting Energy (AWE) hypothesis consists of assuming that the dark sector of cosmology violates the weak equivalence principle (WEP) on cosmological scales, which implies a violation of the strong equivalence principle for…

Astrophysics · Physics 2008-11-26 A. Fuzfa , J. -M. Alimi

Exploring the diversity of dark energy dynamics, we discover a calibration relation, a uniform stretching of the amplitude of the equation of state time variation with scale factor. This defines homogeneous families of dark energy physics.…

Astrophysics · Physics 2009-11-13 Roland de Putter , Eric V. Linder

Recently \citet{PEDE:2019ApJ} proposed a phenomenologically emergent dark energy (PEDE) which consider that the dark energy density evolves as $\widetilde{\Omega}_{\rm{DE}}(z)\,=\,\Omega_{\rm{DE,0}}\left[ 1 - {\rm{tanh}}\left(…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-22 A. Hernández-Almada , Genly Leon , Juan Magaña , Miguel A. García-Aspeitia , V. Motta
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