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Related papers: Cosmic voids and induced hyperbolicity

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We investigate the properties of one--dimensional flux ``voids'' (connected regions in the flux distribution above the mean flux level) by comparing hydrodynamical simulations of large cosmological volumes with a set of observed…

Astrophysics · Physics 2009-11-13 Matteo Viel , Joerg M. Colberg , Tae-Sun Kim

Cosmic voids are the largest and most underdense structures in the Universe. Their properties have been shown to encode precious information about the laws and constituents of the Universe. We show that machine learning techniques can…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-10 Bonny Y. Wang , Alice Pisani , Francisco Villaescusa-Navarro , Benjamin D. Wandelt

Recent observations of high-redshift supernovae seem to suggest that the global geometry of the Universe may be affected by a `cosmological constant', which acts to accelerate the expansion rate with time. But these data by themselves still…

Astrophysics · Physics 2009-10-31 Idit Zehavi , Avishai Dekel

Voids form a prominent aspect of the Megaparsec distribution of galaxies and matter. Not only do they represent a key constituent of the Cosmic Web, they also are one of the cleanest probes and measures of global cosmological parameters.…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-23 Rien van de Weygaert

Cosmic voids are becoming key players in testing the physics of our Universe. Here we concentrate on the abundances and the dynamics of voids as these are among the best candidates to provide information on cosmological parameters. Cai,…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-31 Nelson Padilla , Dante Paz , Marcelo Lares , Laura Ceccarelli , Diego Garcia Lambas , Yan-Chuan Cai , Baojiu Li

Cosmic voids are underdense regions within the large-scale structure of the Universe, spanning a wide range of physical scales - from a few megaparsecs (Mpc) to the largest observable structures. Their distinctive properties make them…

Cosmic voids are promising cosmological laboratories for studying the dark energy phenomenon and alternative gravity theories. They are receiving special attention nowadays in view of the new generation of galaxy spectroscopic surveys,…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-01 Carlos Mauricio Correa

The subject of the paper is the geometry and topology of cosmological spacetimes and vector bundles thereon, which are used to model physical fields propagating in the universe. Global hyperbolicity and factorization properties of the…

Mathematical Physics · Physics 2021-03-31 Zhirayr Avetisyan

Numerical simulations on a 2-dimensional model system showed that voids are induced primarily due to shape anisotropy in binary mixtures of interacting disks. The results of such a simple model account for the key features seen in a variety…

Soft Condensed Matter · Physics 2007-05-23 Gauri R. Pradhan , Sagar A. Pandit , Anil D. Gangal , V. Sitaramam

We demonstrate that light is subject to anomalous (i.e., negative) diffraction when propagating in the presence of hyperbolic dispersion. We show that light propagation in hyperbolic media resembles the dynamics of a quantum particle of…

Starting from an inhomogeneous space-time model of the universe we could recreate a scenario of recent time accelerating universe dominated by Dark Energy type of fluid. The background matter component of such a universe was considered to…

General Relativity and Quantum Cosmology · Physics 2023-02-06 Subhra Bhattacharya

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

Void models provide a possible explanation of the "accelerated expansion" of the Universe without dark energy. To make the conventional void models more realistic, we allow the void, an underdense region around us, to be anisotropic and…

Cosmology and Nongalactic Astrophysics · Physics 2009-06-29 Masayuki Tanimoto , Yasusada Nambu , Kazuhiro Iwata

In a homogeneous and isotropic universe bulk viscosity is the unique viscous effect capable to modify the background dynamics. Effects like shear viscosity or heat conduction can only change the evolution of the perturbations. The existence…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-17 Hermano Velten , Jiaxin Wang , Xinhe Meng

The dark matter in or around the cosmic voids affects their shapes. The thermodynamical properties of dark matter can alter the ellipticity of cosmic voids. Here, applying the dark matter equation of state from the pseudo-isothermal density…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-08 Zeinab Rezaei

We propose an alternative physical mechanism to explain the observed accelerated expansion of the Universe based on the configuration entropy of the cosmic web and its evolution. We show that the sheets, filaments and clusters in the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-20 Biswajit Pandey

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

An approach to cosmological modelling is presented that incorporates the inhomogeneous structure of the Cosmic Web, specifically focusing on the interplay between cosmic voids and density walls. We extend the standard homogeneous and…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-12 John Moffat

The formation of the cosmic structures in the late Universe is considered using Vlasov kinetic approach. The crucial point is the use of the gravitational potential with repulsive term of the cosmological constant which provides a solution…

General Relativity and Quantum Cosmology · Physics 2025-02-26 V. G. Gurzadyan , N. N. Fimin , V. M. Chechetkin

Modern astronomical observations in cosmology provide increasingly strong evidence that the expansion of the Universe is accelerating. Explanations of the cosmic acceleration within the framework of general relativity use the hypothesis…

General Physics · Physics 2015-04-10 I. K. Rozgacheva , A. A. Agapov