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Self-consistent treatment of cosmological structure formation and expansion within the context of classical general relativity may lead to "extra" expansion above that expected in a structureless universe. We argue that in comparison to an…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-01 Boudewijn F. Roukema , Jan J. Ostrowski , Thomas Buchert , Pierre Mourier

We perform large-scale cosmological simulations that solve Einstein's equations directly via numerical relativity. Starting with initial conditions sampled from the cosmic microwave background, we track the emergence of a cosmic web without…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-27 Hayley J. Macpherson , Daniel J. Price , Paul D. Lasky

The self-gravitating gas in the Newtonian limit is studied in the presence of dark energy with a linear and constant equation of state. Entropy extremization associates to the isothermal Boltzmann distribution an effective density that…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-15 Zacharias Roupas , Minos Axenides , George Georgiou , Emmanuel N. Saridakis

We test the hypothesis that globular clusters form in supergiant molecular clouds within high-redshift galaxies. Numerical simulations demonstrate that such large, dense, and cold gas clouds assemble naturally in current hierarchical models…

Astrophysics · Physics 2010-07-27 Oleg Y. Gnedin , Jose L. Prieto

We are concerned with spherically symmetric solutions to the Euler equations for the multi-dimensional compressible fluids, which have many applications in diverse real physical situations. The system can be reduced to one dimensional…

Analysis of PDEs · Mathematics 2019-08-20 Feimin Huang , Tianhong Li , Difan Yuan

The properties of old globular cluster systems in galaxy halos are used to infer quantitative constraints on aspects of generic star (cluster) formation. First, the spatial distribution of globulars in three large galaxies, together with…

Astrophysics · Physics 2007-05-23 Dean E. McLaughlin

The universe is viewed as a dust gas filling a sphere and floating in infinite empty space. Einstein's gravitational equations are applied to this case together with appropriate boundary values. The equations are solved for initial…

General Relativity and Quantum Cosmology · Physics 2015-12-01 Ingo Müller , Wolf Weiss

The solution of the dark energy problem in models without scalars is presented. It is shown that a late-time accelerating cosmology may be generated by an ideal fluid with some implicit equation of state.

High Energy Physics - Theory · Physics 2007-05-23 O. Gorbunova

Rich clusters of galaxies are the most massive virialized systems known. Even though they contain only a small fraction of all galaxies, rich clusters provide a powerful tool for the study of galaxy formation, dark matter, large-scale…

Astrophysics · Physics 2007-05-23 Neta A. Bahcall

Using recent developments in the theory of globally defined expanding compressible gases, we construct a class of global-in-time solutions to the compressible 3-D Euler-Poisson system without any symmetry assumptions in both the…

Analysis of PDEs · Mathematics 2017-12-04 Mahir Hadzic , Juhi Jang

A model of an emergent universe is formulated using the mechanism of particle creation. Here the universe is considered as a non-equilibrium thermodynamical system with dissipation due to particle creation mechanism. The universe is chosen…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Subenoy Chakraborty

In this brief note, we would like to point out that large-scale structures like galaxies and superclusters would arise quite naturally in the universe.

Astrophysics · Physics 2007-05-23 B. G. Sidharth

We develop a new approach to building cosmological models, in which small pieces of perturbed Minkowski space are joined together at reflection-symmetric boundaries in order to form a global, dynamical space-time. Each piece of this…

General Relativity and Quantum Cosmology · Physics 2016-04-12 Viraj A. A. Sanghai , Timothy Clifton

We prove global in time existence of solutions of the Euler compressible equations for a Van der Waals gas when the density is small enough in $\H{m}$, for $m$ large enough. To do so, we introduce a specific symmetrisation allowing areas of…

Analysis of PDEs · Mathematics 2010-04-08 Magali Mercier

Extended gas haloes around galaxies are a ubiquitous prediction of galaxy formation scenarios. However, the density profiles of this hot halo gas is virtually unknown, although various profiles have been suggested on theoretical grounds. In…

Astrophysics · Physics 2009-11-11 Steen H. Hansen , Jesper Sommer-Larsen

After two decades of direct dynamical simulation of large-scale structure in the universe, it is safe to say the subject is now mature. Still, there are parts of the problem that are less well developed than others. In general, the…

Astrophysics · Physics 2007-05-23 August E. Evrard

The thermodynamic equilibrium conditions for compact structures composed by mass varying particles are discussed assuming that the so-called dynamical mass behaves like an additional extensive thermodynamic degree of freedom. It then…

General Relativity and Quantum Cosmology · Physics 2011-06-07 Alex E. Bernardini , O. Bertolami

This article reviews the prevailing paradigm for how galaxies and larger structures formed in the universe: gravitational instability. Basic observational facts are summarized to motivate the standard cosmological framework underlying most…

Astrophysics · Physics 2009-10-22 Edmund Bertschinger

First postinflationary stage of the Universe evolution is considered in more detail. It is shown that heavy particles with mass $M_{H}\sim M_{GUT}$ arising at the Universe at phase transitions at Grand Unification Energies behave like ideal…

High Energy Physics - Phenomenology · Physics 2007-05-23 I. Dymnikova , M. Krawczyk

Universe structure emerges in the unreduced, complex-dynamic interaction process with the simplest initial configuration (two attracting homogeneous fields, quant-ph/9902015). The unreduced interaction analysis gives intrinsically creative…

General Physics · Physics 2007-05-23 Andrei P. Kirilyuk