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Related papers: Modelling Inhomogeneity in Szekeres Spacetime

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Effective models of gravitational collapse in loop quantum gravity for the Lema\^itre-Tolman-Bondi spacetime predict that collapsing matter reaches a maximum finite density, bounces, and then expands outwards. We show that in the marginally…

General Relativity and Quantum Cosmology · Physics 2024-04-23 Francesco Fazzini , Viqar Husain , Edward Wilson-Ewing

We illuminate the altered evolution of galaxies in clusters compared to the field by tracking galaxies in the IllustrisTNG300 simulation as they enter isolated clusters of mass $10^{13} < M_{\rm 200, mean} / {\rm M}_\odot < 10^{15}$ (at…

Astrophysics of Galaxies · Physics 2024-05-30 Stephanie O'Neil , Josh Borrow , Mark Vogelsberger , Hanzhang Zhao , Bing Wang

The evolution of an inhomogeneous universe composed entirely of matter is followed from an early, nearly uniform state until the time when the inhomogeneities have begun to grow large. The particular distribution of matter studied in this…

Cosmology and Nongalactic Astrophysics · Physics 2010-11-10 Hael Collins

We investigate a spherical collapse model with and without the spatial curvature. We obtain the exact solutions of dynamical quantities such as the ratio of the scale factor to its value at the turnaround epoch and the ratio of the…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-29 Seokcheon Lee

This paper covers the material of our two talks. We describe a series of projects based upon perturbative expansions to follow the gravitational evolution of the one point probability distribution functions (PDFs) for the density contrast…

Astrophysics · Physics 2007-05-23 F. R. Bouchet , R. Juszkiewicz

We consider the existence of an "inflaton" described by an homogeneous scalar field in the Szekeres cosmological metric. The gravitational field equations are reduced to two families of solutions which describe the homogeneous…

General Relativity and Quantum Cosmology · Physics 2018-10-17 John D. Barrow , Andronikos Paliathanasis

We measure the diversity of galaxy groups and clusters with mass M>1E13/h Msun, in terms of the star formation history of their galaxy populations, for the purpose of constraining the mass scale at which environmentally-important processes…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Michael L. Balogh , Sean L. McGee

We introduce a simple spherical model whose structural properties are similar to the ones generated by models with directional interactions, by employing a binary mixture of large and small hard spheres, with a square-well attraction acting…

Disordered Systems and Neural Networks · Physics 2009-11-13 Emanuela Zaccarelli , Francesco Sciortino , Piero Tartaglia

We present a special case of the Stephani solution with spherical symmetry while considering different values of spatial curvature. We investigate the dynamics of the universe evolution in our model, build the R--T-regions for the resulting…

General Relativity and Quantum Cosmology · Physics 2020-02-06 I. Bormotova , E. Kopteva , M. Churilova , Z. Stuchlik

In this work, we study the large-scale structure of homogeneous flows displaying high density contrasts and small turbulent Mach numbers. Following Batchelor & Proudman (PTRSA 258, 1956), we draw an analogy between this configuration and…

Fluid Dynamics · Physics 2024-02-26 Olivier Soulard , Jérôme Griffond , Benoît-Joseph Gréa , Giovani Viciconte

Averaging and evolving inhomogeneities are non-commuting operations. This implies the existence of deviations of an averaged model from the standard Friedmann-Lemaitre cosmologies. We quantify these deviations, encoded in a backreaction…

Astrophysics · Physics 2013-03-26 Thomas Buchert , Martin Kerscher , Christian Sicka

Horizons of black branes have an associated entropy current with non-negative divergence. We compute this divergence in a late-time transseries expansion for an inhomogeneous system evolving towards a maximally symmetric asymptotically…

High Energy Physics - Theory · Physics 2020-07-01 Aron Jansen , Ben Meiring

We study how inhomogeneities modify large scale parameters in General Relativity. For a particular model, we obtain exact results: we compare an infinite string of extremal black holes to a corresponding smooth line with the same mass and…

General Relativity and Quantum Cosmology · Physics 2011-03-31 Martin Rocek , Patrick van Nieuwenhuizen

Supercooled liquids exhibit complicated dynamical behaviors: At the microscopic level, the dynamics is heterogeneous spatially, known as dynamic heterogeneity. At the macroscopic level, the shear viscosity $\eta$ decreases as shear rate…

Soft Condensed Matter · Physics 2025-09-01 Ke-Qi Zeng , Dong-Xu Yu , Zhe Wang

We study the evolution of linear density perturbations in a large spherical void universe which accounts for the acceleration of the cosmic volume expansion without introducing dark energy. The density contrast of this void is not large…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-07 Ryusuke Nishikawa , Chul-Moon Yoo , Ken-ichi Nakao

We study second-order cosmological perturbations in scalar-tensor models of dark energy that satisfy local gravity constraints, including f(R) gravity. We derive equations for matter fluctuations under a sub-horizon approximation and…

Astrophysics · Physics 2010-10-12 Takayuki Tatekawa , Shinji Tsujikawa

We compute the skewness of the matter distribution arising from non-linear evolution and from non-Gaussian initial perturbations. We apply our result to a very generic class of models with non-Gaussian initial conditions and we estimate…

Astrophysics · Physics 2009-12-30 Ruth Durrer , Roman Juszkiewicz , Martin Kunz , Jean-Philippe Uzan

We discuss the spatiotemporal behavior of local density and its relation to dynamical heterogeneity in a highly supercooled liquid by using molecular dynamics simulations of a binary mixture with different particle sizes in two dimensions.…

Soft Condensed Matter · Physics 2015-03-20 Hayato Shiba , Takeshi Kawasaki

After decades of searching, cosmological time dilation was recently identified in the timescale of variability seen in distant quasars. Here, we expand on the previous analysis to disentangle this cosmological signal from the influence of…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-14 Brendon J. Brewer , Geraint F. Lewis , Yuan Li

We study the Universe at the late stage of its evolution and deep inside the cell of uniformity. At such a scale the Universe is highly inhomogeneous and filled with discretely distributed inhomogeneities in the form of galaxies and groups…

General Relativity and Quantum Cosmology · Physics 2016-08-25 Mariam Bouhmadi-López , João Morais , Alexander Zhuk