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The presence of dark energy in the Universe is inferred directly and indirectly from a large body of observational evidence. The simplest and most theoretically appealing possibility is the vacuum energy density (cosmological constant).…

Astrophysics · Physics 2008-11-26 J. S. Alcaniz

We study the effects of various phenomena which may have happened in the early universe on the spectrum of inflationary gravitational waves. The phenomena include phase transitions, entropy productions from non-relativistic matter, the…

High Energy Physics - Phenomenology · Physics 2015-06-16 Ryusuke Jinno , Takeo Moroi , Kazunori Nakayama

We conjecture that the total quantum entanglement of matter and vacuum in the universe tends to increase with time, like entropy, and that an effective force is associated with this tendency. We also suggest that gravity and dark energy are…

High Energy Physics - Theory · Physics 2015-09-16 Jae-Weon Lee , Hyeong-Chan Kim , Jungjai Lee

Under the assumption that General Relativity (GR) correctly describes the phenomenology of our Universe, astronomical observations provide compelling evidence that (1) the dynamics of cosmic structure is dominated by dark matter (DM), an…

Astrophysics · Physics 2008-02-19 A. Diaferio

If general relativity (GR) describes the expansion of the Universe, the observed cosmic acceleration implies the existence of a `dark energy'. However, while the Universe is on average homogeneous on large scales, it is inhomogeneous on…

Astrophysics · Physics 2008-11-26 Aseem Paranjape , T. P. Singh

Old and new puzzles of cosmology are reexamined from the point of view of quantum theory of the universe developed here. It is shown that in proposed approach the difficulties of the standard cosmology do not arise. The theory predicts the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. E. Kuzmichev , V. V. Kuzmichev

The physical nature of the presently dominating enigmatic dark energy in the expanding universe is demonstrated to be explainable as an excess of the kinetic energy with respect to its potential energy. According to traditional Friedman…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 Arved Sapar

We consider the Wheeler-DeWitt equation near the horizon of the black hole where the entangled vacuum state is chosen as the static universe state. Then, using the entangled property of the vacuum state, we investigate the dynamical…

General Relativity and Quantum Cosmology · Physics 2022-06-22 H. Hadi , F. Darabi

We derive a model of dark energy which evolves with time via the scale factor. The equation of state $\omega=(1-2\alpha)/(1+2\alpha)$ is studied as a function of a parameter $\alpha$ introduced in this model. In addition to the recent…

General Relativity and Quantum Cosmology · Physics 2017-06-20 Hemza Azri , A. Bounames

Based on Newton's laws reformulated in the Hamiltonian dynamics combined with statistical mechanics, we formulate a statistical mechanical theory supporting the hypothesis of a closed oscillating universe. We find that the behaviour of the…

Statistical Mechanics · Physics 2015-05-13 A. Perez-Madrid , I. Santamaria-Holek

Coherent states consist of superposition of infinite number of particles and do not have a classical analogue. We study their evolution in a FLRW cosmology and show that only when full quantum corrections are considered, they may survive…

High Energy Physics - Phenomenology · Physics 2015-08-26 Houri Ziaeepour

A general equation of state is considered for analysing the possible behaviors for (Early) dark energy that alleviates the Hubble parameter tension problem. By departing from the possible evolution for the (Early) dark energy density and…

General Relativity and Quantum Cosmology · Physics 2021-05-25 Shin'ichi Nojiri , Sergei D. Odintsov , Diego Saez-Chillon Gomez , German S. Sharov

The strong proper time dilation and radial contraction in the gravitational field of compact sources leads to a frozen state of matter. It is shown that the falling particles and photons can not cross the gravitational radius due to the…

General Physics · Physics 2014-12-17 Zahid Zakir

Dark matter represents currently an outstanding problem in both cosmology and particle physics. In this review we discuss the possible explanations for dark matter and the experimental observables which can eventually lead to the discovery…

High Energy Physics - Phenomenology · Physics 2021-04-26 A. Arbey , F. Mahmoudi

For the Poincare gauge theory of gravity we consider the dynamical scalar torsion mode in a cosmological context. We explore in particular the possibility of using dynamical torsion to explain the current state of the accelerating Universe.…

Astrophysics · Physics 2008-11-26 Hwei-Jang Yo , James M. Nester

The early stages of the universe evolution are discussed according to the hot big bang model and the grand unified theories. The shortcomings of big bang are summarized and their resolution by inflationary cosmology is sketched.…

High Energy Physics - Phenomenology · Physics 2020-05-18 George Lazarides

The phantom dark energy remarkably boosts our prehension of the accelerating Universe. Various models are widely discussed in the phantom Universe without bulk viscosity. From the hydrodynamics' point of view, it is natural to introduce the…

General Relativity and Quantum Cosmology · Physics 2020-06-11 Ji-Yao Wang , Chao-Jun Feng , Xiang-Hua Zhai , Xin-Zhou Li

We review the current standard model for the evolution of the Universe from an early inflationary epoch to the complex hierarchy of structure seen today. We summarize and provide key references for the following topics: observations of the…

Astrophysics · Physics 2009-06-23 Bharat Ratra , Michael S. Vogeley

According to the inflationary scenario of cosmology, all structure in the Universe can be traced back to primordial fluctuations during an accelerated (inflationary) phase of the very early Universe. A conceptual problem arises due to the…

Astrophysics · Physics 2010-04-28 Claus Kiefer , David Polarski

One possible description of the very early stages of the evolution of the universe is provided by Chaotic Inflationary Cosmology. For that model the role of the inflaton field is played by quantum gravitational effects. We study if such a…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Pablo Mora
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