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Related papers: Relativistic cosmological hydrodynamics

200 papers

For general number of spatial dimensions we investigate the cosmological dynamics driven by a cosmological constant and by a source with barotropic equation of state. It is assumed that for both those sources the energy density can be…

General Relativity and Quantum Cosmology · Physics 2022-11-09 A. A. Saharian , R. M. Avagyan , E. R. Bezerra de Mello , V. Kh. Kotanjyan , T. A. Petrosyan , H. G. Babujyan

After introducing gauge-invariant cosmological perturbation theory we give an improved set of governing equations for multiple fluids including energy transfer. Having defined adiabatic and entropic perturbations we derive the…

Astrophysics · Physics 2007-05-23 Karim A. Malik

We outline the content and theoretical support for the proposal of "hydrodynamics on (mini)superspace" (or a non-linear extension of quantum cosmology) as an effective framework for quantum gravity in a cosmological context. The basis for…

General Relativity and Quantum Cosmology · Physics 2024-03-19 Daniele Oriti

The relation between the long wavelength limit of solutions to the cosmological perturbation equations and the perturbations of solutions to the exactly homogeneous background equations is investigated for scalar perturbations on spatially…

General Relativity and Quantum Cosmology · Physics 2009-10-30 H. Kodama , T. Hamazaki

Without invoking a perturbative expansion, we define the cosmological curvature perturbation, and consider its behaviour assuming that the universe is smooth over a sufficiently large comoving scale. The equations are simple, resembling…

Astrophysics · Physics 2009-10-09 David H. Lyth , Karim A. Malik , Misao Sasaki

In this paper we study the evolution of cosmological perturbations through a nonsingular bouncing universe using covariant perturbation theory and examine the validity of linear perturbation theory. The bounce is modeled by a two component…

General Relativity and Quantum Cosmology · Physics 2014-05-16 Atanu Kumar

The formalism to treat quantization and evolution of cosmological perturbations of multiple fluids is described. We first construct the Lagrangian for both the gravitational and matter parts, providing the necessary relevant variables and…

General Relativity and Quantum Cosmology · Physics 2016-02-01 Patrick Peter , Nelson Pinto-Neto , Sandro Dias Pinto Vitenti

Present expansion stage of the universe is believed to be mainly governed by the cosmological constant, collisionless dark matter and baryonic matter. The latter two components are often modeled as zero-pressure fluids. In our previous work…

Astrophysics · Physics 2009-06-23 J. Hwang , H. Noh

We present a new solution of relativistic hydrodynamics in 1+3 dimensions which depends on both the transverse coordinate and rapidity. At early times the flow expands dominantly longitudinally in a non-boost-invariant manner, and at late…

High Energy Physics - Phenomenology · Physics 2016-02-03 Yoshitaka Hatta , Bo-Wen Xiao , Di-Lun Yang

The linear cosmological perturbation theory of almost homogeneous and isotropic perfect fluid and scalar field universes is reconsidered and formally simplified. Using the existence of a covariant conserved quantity on large perturbation…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Winfried Zimdahl

Inhomogeneous cosmological perturbation equations are derived in loop quantum gravity, taking into account corrections in particular in gravitational parts. This provides a framework for calculating the evolution of modes in structure…

There are now evidences that the cosmological constant $\Lambda$ has a non-zero positive value. Alternative scenarios to a pure cosmological constant model are provided by quintessence, an effective negative pressure fluid permeating the…

Astrophysics · Physics 2008-11-26 Antonio Vale , Jose' P. S. Lemos

This is the first in a series of papers on the construction and validation of a three-dimensional code for general relativistic hydrodynamics, and its application to general relativistic astrophysics. This paper studies the consistency and…

General Relativity and Quantum Cosmology · Physics 2009-10-31 J. A. Font , M. Miller , W. Suen , M. Tobias

We discuss cosmological perturbation theory at third order, deriving the gauge transformation rules for metric and matter perturbations, and constructing third order gauge invariant quantities. We present the Einstein tensor components, the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Adam J. Christopherson , Karim A. Malik

The non-perturbative curvature inhomogeneities induced by relativistic viscous fluids are not conserved in the large-scale limit. However when the bulk viscosity is a function of the total energy density of the plasma (or of the trace of…

High Energy Physics - Theory · Physics 2015-08-06 Massimo Giovannini

In this paper, in an extended theory of gravity, we have presented bouncing cosmological model at the backdrop of an isotropic, homogeneous space-time, in presence of general relativistic hydrodynamics (GRH). The scale factor has been…

General Relativity and Quantum Cosmology · Physics 2023-03-29 A. Y. Shaikh , Sankarsan Tarai , S. K. Tripathy , B. Mishra

We investigate the large scale cosmological perturbation in the Universe with multiple perfect fluids. Using the long-wavelength approximation with Hamilton-Jacobi method, we derive the formula for the gauge invariant comoving curvature…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Yasusada Nambu , Shin-ichi Ohokata

The description of general relativistic radiation hydrodynamics in spherical symmetry is presented in natural coordinate choices. For hydrodynamics, comoving coordinates are chosen, and the momentum phase space for the radiation particles…

We present hydrodynamic equations with relativistic pressure and velocity in the presence of weak gravity, in a cosmological context. Previously we consistently derived special relativistic hydrodynamic equations with weak gravity in…

General Relativity and Quantum Cosmology · Physics 2018-11-14 Hyerim Noh , Jai-chan Hwang , Chan-Gyung Park

General relativity and its cosmological solution predicts the existence of tensor modes of perturbations evolving on top of our Friedman-Lema\^itre-Robertson-Walker expanding Universe. Being gauge invariant and not necessarily coupled to…

General Relativity and Quantum Cosmology · Physics 2023-01-20 Amaury Micheli , Patrick Peter