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Related papers: Flat Universe with Hyperbolic Voids

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Cosmic voids - the low density regions in the Universe - as characteristic features of the large scale matter distribution, are known for their hyperbolic properties. The latter implies the deviation of photon beams due to their…

General Relativity and Quantum Cosmology · Physics 2020-12-03 M. Samsonyan , A. A. Kocharyan , A. Stepanian , V. G. Gurzadyan

In this talk we shall show a perfect fluid cosmological model and its properties. The model possesses an orthogonally transitive abelian two-dimensional group of isometries that corresponds to cylindrical symmetry. The matter content is a…

General Relativity and Quantum Cosmology · Physics 2009-06-01 L. Fernández Jambrina

Cosmic voids as typical under-density regions in the large scale Universe are known for their hyperbolic properties as an ability to deviate the photon beams. The under-density then is acting as the negative curvature in the hyperbolic…

General Relativity and Quantum Cosmology · Physics 2021-04-07 M. Samsonyan , A. A. Kocharyan , A. Stepanian , V. G. Gurzadyan

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

Recent evidence indicates that the Universe is open, i.e., spatially hyperbolic, longstanding theoretical preferences to the contrary notwithstanding. This makes it possible to select a vacuum state, Fock space, and particle definition for…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Ian H. Redmount

The semi-classical approach to the quantum geometrodynamical model is used for the description of the properties of the universe on extremely small spacetime scales. Quantum theory for a homogeneous, isotropic and closed universe is…

General Relativity and Quantum Cosmology · Physics 2009-10-21 V. E. Kuzmichev , V. V. Kuzmichev

Strong hyperbolicity is a coarse notion of negative curvature, stronger than Gromov hyperbolicity, that includes all CAT(-k) metrics for k positive and allows the use of dynamical techniques available in negative curvature, such as…

Geometric Topology · Mathematics 2026-05-15 Meenakshy Jyothis , Dídac Martínez-Granado

In metric-affine gravity, both the gravitational and matter actions depend not just on the metric, but also on the independent affine connection. Thus matter can be modeled as a hyperfluid, characterized by both the energy-momentum and…

General Relativity and Quantum Cosmology · Physics 2025-03-25 Ilaria Andrei , Damianos Iosifidis , Laur Järv , Margus Saal

The description of the universe evolving in time according to general relativity is given in comparison with the quantum description of the same universe in terms of semiclassical wave functions. The spacetime geometry is determined by the…

General Relativity and Quantum Cosmology · Physics 2015-12-09 V. E. Kuzmichev , V. V. Kuzmichev

Singularity theorems demonstrate the inevitable breakdown of the concept of continuous, classical spacetime under highly general conditions. Quantum gravity is expected to intervene to avoid singularities and models so far hint towards…

General Relativity and Quantum Cosmology · Physics 2024-08-30 Raúl Carballo-Rubio , Stefano Liberati , Vania Vellucci

Recently many people have discussed the possibility that the universe is hyperbolic and was in an inflationary phase in the early stage. Under these assumptions, it is shown that the universe cannot have compact hyperbolic time-slices.…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Akihiro Ishibashi , Tatsuhiko Koike , Masaru Siino , Sadayoshi Kojima

Two entropic dynamical models are considered. The geometric structure of the statistical manifolds underlying these models is studied. It is found that in both cases, the resulting metric manifolds are negatively curved. Moreover, the…

Chaotic Dynamics · Physics 2009-11-13 Carlo Cafaro , S. A. Ali

Geometry of the universe has always intrigued mathematicians and cosmologists. Recent results from the Wilkinson Microwave Anisotropy Project (WMAP) indicate that the visible universe is incredibly flat. This apparent flatness could be due…

General Relativity and Quantum Cosmology · Physics 2013-09-24 Selcuk S. Bayin

We reexamine the possibility of the detection of the cosmic topology in nearly flat hyperbolic Friedmann-Lemaitre-Robertson-Walker (FLRW) universes by using patterns repetition. We update and extend our recent results in two important ways:…

General Relativity and Quantum Cosmology · Physics 2009-11-07 G. I. Gomero , M. J. Reboucas , R. Tavakol

The degree of randomness in the cosmic microwave background (CMB) maps has been shown to be measurable and indicative of the hyperbolic effect of voids on the propagation of the photon beams. In terms of an introduced porosity parameter, we…

Astrophysics · Physics 2009-11-13 V. G. Gurzadyan , A. A. Kocharyan

This talk is about solving cosmological equations analytically without approximations, and discovering new phenomena that could not be noticed with approximate solutions. We found all the solutions of the Friedmann equations for a specific…

General Relativity and Quantum Cosmology · Physics 2011-09-30 Itzhak Bars

The only known general base to eliminate the vacuum divergencies of quantized matter fields in quantum geometrodynamics is the fermion-boson supersymmetry. The topological effect of the closed Universe -- discretization of the vacuum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. B. Savchenko , V. A. Savchenko , G. M. Vereshkov

Time-independent Hamiltonian flows are viewed as geodesic flows in a curved manifold, so that the onset of chaos hinges on properties of the curvature two-form entering into the Jacobi equation. Attention focuses on ensembles of orbit…

Astrophysics · Physics 2009-10-30 Henry E. Kandrup

Assuming that the background geometry is filled with free gas consisting of matter and radiation and no phase transitions being occurred in the early Universe, we discuss the thermodynamics of this {\it closed} system using classical…

General Relativity and Quantum Cosmology · Physics 2015-05-30 A. Tawfik , H. Magdy
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