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The currently released datasets of the observational surveys reveal the redshift dependence of the physical features of cosmic voids. We study the void induced hyperbolicity, that is the deviation of the photon beams propagating the voids,…

General Relativity and Quantum Cosmology · Physics 2021-08-13 M. Samsonyan , A. A. Kocharyan , A. Stepanian , V. G. Gurzadyan

Idealizing matter as a pressureless fluid and representing its motion by a peculiar--velocity field superimposed on a homogeneous and isotropic Hubble expansion, we apply (Lagrangian) spatial averaging on an arbitrary domain $\cal D$ to the…

Astrophysics · Physics 2011-09-29 Thomas Buchert , Juergen Ehlers

In a recent paper [arXiv:1206.4916] by T. Padmanabhan, it was argued that our universe provides an ideal setup to stress the issue that cosmic space is emergent as cosmic time progresses and that the expansion of the universe is due to the…

General Relativity and Quantum Cosmology · Physics 2012-11-09 Rong-Gen Cai

We derive an effective gravitational potential, induced by the quantum wavefunction of a physical vacuum of a self-gravitating configuration, while the vacuum itself is viewed as the superfluid described by the logarithmic quantum wave…

General Relativity and Quantum Cosmology · Physics 2020-12-01 Konstantin G. Zloshchastiev

We build an exact inhomogeneous universe composed of a central flat Friedmann zone up to a small redshift $z_1$, a thick shell made of anisotropic matter, an hyperbolic Friedmann metric up to the scale where dimming galaxies are observed…

Cosmology and Nongalactic Astrophysics · Physics 2010-06-17 Stefano Viaggiu

A quantum object is extended by virtue of quantum uncertainty. Subjected to gravity, it therefore experiences tidal forces and other relativistic effects. As a result, entropy and purity affect geodesic motion and acquire weight, an…

Quantum Physics · Physics 2025-06-18 Joseph Balsells , Martin Bojowald

We analyze two different algorithms for constructing weakly inhomogeneous models for the low-redshift Universe, in order to provide a tool for testing the geodesic dynamics, within the sphere of validity for the Universe acceleration. We…

General Relativity and Quantum Cosmology · Physics 2020-07-14 P. Marcoccia , G. Montani

A cosmological model with an inhomogeneous viscous dark fluid coupled with dark matter in a flat Friedman-Robertson-Walker universe is investigated. The influence of dark matter on the behavior of an inhomogeneous viscous fluid of this…

General Relativity and Quantum Cosmology · Physics 2015-06-22 E. Elizalde , V. V. Obukhov , A. V. Timoshkin

Bounce cosmological models containing a dark viscous fluid in a spatially flat Friedmann-Robertson-Walker (FRW) universe are considered. The universe evolution is described in terms of generalized equation of state (EoS) parameters, in…

General Relativity and Quantum Cosmology · Physics 2024-11-19 E. Elizalde , A. V. Yurov , A. V. Timoshkin

We present a brief history of the construction of models of the universe, followed by calculations of quantitative characteristics of basic geometric and kinematic properties of the Standard Cosmological Model ($\Lambda$CDM). Using the…

General Relativity and Quantum Cosmology · Physics 2026-04-23 D. I. Nagirner , S. G. Jorstad , A. V. Dementyev

Inspired by the entropy-area relation of black hole thermodynamics, we study the thermodynamics of cosmological apparent horizon in a spatially flat Friedmann-Robertson-Walker (FRW) universe in the framework of an Extended Uncertainty…

General Relativity and Quantum Cosmology · Physics 2024-08-29 Maryam Roushan , Narges Rashidi , Kourosh Nozari

The Einstein-Hilbert worldspace action is used to investigate the dynamics of extended object. In the Robertson-Walker worldspace, this is seen to introduce a pressureless density which could contribute to dark matter. Such pressureless…

Astrophysics · Physics 2007-05-23 U. Khanal

We make use of the fact that the optical geometry near a static non-degenerate Killing horizon is asymptotically hyperbolic to investigate universal features of black hole physics. We show how the Gauss-Bonnet theorem allows certain lensing…

General Relativity and Quantum Cosmology · Physics 2009-11-13 G. W. Gibbons , C. M. Warnick

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

The linearly polarized Gowdy $T^3$ model with a massless scalar field with the same symmetries as the metric is quantized by applying a hybrid approach. The homogeneous geometry degrees of freedom are loop quantized, fact which leads to the…

General Relativity and Quantum Cosmology · Physics 2013-01-30 Daniel Martín-de Blas , Mercedes Martín-Benito , Guillermo A. Mena Marugán

Production of gravitational vacuum defects and their contribution to the energy density of our Universe are discussed. These topological microstructures (defects) could be produced in the result of creation of the Universe from "nothing"…

General Relativity and Quantum Cosmology · Physics 2008-01-03 V. Burdyuzha , G. Vereshkov , J. Pacheco

Whereas the nature of dark components in the Universe remains unknown, alternative models of gravity have been developed to offer a geometric explanation to the origin of such components. In this work we use the Minimal Geometric…

General Relativity and Quantum Cosmology · Physics 2020-04-03 Francisco X. Linares Cedeño , Ernesto Contreras

Within the framework of geodetic brane gravity, the Universe is described as a 4-dimensional extended object evolving geodetically in a higher dimensional flat background. In this paper, by introducing a new pair of canonical fields…

General Relativity and Quantum Cosmology · Physics 2009-11-07 David Karasik , Aharon Davidson

The space ML(F) of measured geodesic laminations on a given closed hyperbolic surface F has a canonical linear structure arising in fact from different sources in 2-dimensional hyperbolic (earthquake theory) or complex projective (grafting)…

Differential Geometry · Mathematics 2007-05-23 Francesco Bonsante

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
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