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Related papers: The flatness of the Universe is robust

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We consider the model of a false vacuum bubble with a thin wall where the surface energy density is composed of two different components, "domain-wall" type and "dust" type, with opposite signs. We find stably oscillating solutions, which…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Eduardo I. Guendelman , Nobuyuki Sakai

In this paper, we consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. At these scales, the Universe is filled with inhomogeneously distributed discrete structures (galaxies, groups and clusters…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Alvina Burgazli , Maxim Eingorn , Alexander Zhuk

In this paper, we consider the Universe deep inside of the cell of uniformity. At these scales, the Universe is filled with inhomogeneously distributed discrete structures (galaxies, groups and clusters of galaxies), which disturb the…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-25 Maxim Eingorn , Alexander Zhuk

The paper uses geometrical arguments to derive equations with relevance for cosmology; 5-dimensional spacetime is assumed because it has been shown in other works to provide a setting for significant unification of different areas of…

General Physics · Physics 2008-01-29 Jose B. Almeida

We argue that there has been substantial evolution in the ellipticity of rich galaxy clusters between 0 < z < 0.1, and suggest that this is additional evidence for a low matter-density Universe.

Astrophysics · Physics 2009-11-07 Adrian L. Melott , Scott W. Chambers , Christopher J. Miller

The Standard Cosmological Model of the 1980's is no more. I describe the definitive evidence that the density of matter is insufficient to result in a flat universe, as well as the mounting evidence that the cosmological constant is not…

High Energy Physics - Phenomenology · Physics 2009-10-31 Lawrence M. Krauss

Flat and open universe models are considered, containing a mixture of cold matter (dust) and radiation interacting only through gravity, with the aim of studying their stability with respect to linear scalar perturbations. To this end the…

Astrophysics · Physics 2015-06-24 Marco Bruni , Kamilla Piotrkowska

Two new one-parameter tracking behavior dark energy representations $\omega=\omega_0/(1+z)$ and $\omega=\omega_0 e^{z/(1+z)}/(1+z)$ are used to probe the geometry of the Universe and the property of dark energy. The combined type Ia…

Astrophysics · Physics 2009-11-10 Yungui Gong , Yuan-Zhong Zhang

We develop a new model for the Universe based on two key assumptions: first, the inertial energy of the Universe is a constant, and second, the total energy of a particle, the inertial plus the gravitational potential energy produced by the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Hossein Shojaie , Mehrdad Farhoudi

From the axiom of the unrestricted repeatability of all experiments, Bondi and Gold argued that the universe is in a stable, self-perpetuating equilibrium state. This concept generalizes the usual cosmological principle to the perfect…

Astrophysics · Physics 2007-05-23 Thomas B. Andrews

This paper reviews some of the results of the Planck collaboration and shows how to compute the distance from the surface of last scattering, the distance from the farthest object that will ever be observed, and the maximum radius of a…

General Physics · Physics 2020-02-27 Kevin Cahill

We introduce a string-inspired model for a bouncing/cyclic universe, utilizing the scalar-tachyon coupling as well as contribution from curvature in a closed universe. The universe undergoes the locked inflation, tachyon matter dominated…

General Relativity and Quantum Cosmology · Physics 2014-01-22 Changhong Li , Lingfei Wang , Yeuk-Kwan E. Cheung

In the present article, which is the first part of a work in three parts, we build an equation of quantum gravity. This equation is tensorial, is equivalent to general relativity in vacuum, but differs completely from general relativity…

General Physics · Physics 2007-11-25 Christophe Real

Observational evidence suggests that the large scale dynamics of the universe is presently dominated by dark energy, meaning a non-luminous cosmological constituent with a negative value of the pressure to density ratio $w=P/\rho$, which…

High Energy Physics - Theory · Physics 2009-11-11 R. A. Battye , B. Carter , E. Chachoua , A. Moss

One can make the very simple hypothesis that the Universe is the inside of an hypersphere in 4 dimensions, where our 3-dimensional world consists of hypersurfaces at different radii. Based on this assumption it is possible to show that…

General Physics · Physics 2007-05-23 Jose B. Almeida

Modeling of matter bounce in $f(R,T)$ gravity has been presented with no violation of the null energy condition. Only a closed universe with negative pressure is allowed in good agreement with some recent observations which favor a universe…

General Relativity and Quantum Cosmology · Physics 2022-06-22 Vinod Kumar Bhardwaj , Anirudh Pradhan , Nasr Ahmed , A. A. Shaker

Cosmological data have provided new constraints on the number of neutrino species and the neutrino mass. However these constraints depend on assumptions related to the underlying cosmology. Since a correlation is expected between the number…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-30 Aaron Smith , Maria Archidiacono , Asantha Cooray , Francesco De Bernardis , Alessandro Melchiorri , Joseph Smidt

The general world model for homogeneous and isotropic universe has been roposed. For this purpose, we introduce a global and fiducial system of reference (world reference frame) constructed on a 5-dimensional space-time that is embedding…

Astrophysics · Physics 2008-03-04 Chan-Gyung Park

In a room with five cosmologists there there may easily be ten theories of cosmogenesis. Cosmogenesis is a popular topic for speculation because it is philosophically deep and because such speculations are unlikely to be proven wrong in the…

General Relativity and Quantum Cosmology · Physics 2011-07-27 Ronald J. Adler

We use numerical relativity simulations to explore the conditions for a canonical scalar field $\phi$ minimally coupled to Einstein gravity to generate an extended phase of slow contraction that robustly smooths the universe for a wide…

General Relativity and Quantum Cosmology · Physics 2022-08-29 Timo Kist , Anna Ijjas
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