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Related papers: Two-Component Cosmological Fluids with Gravitation…

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We consider the cosmological system with two interacting fluids: dark energy and dark matter, in a homogeneous and isotropic universe with dissipation. The modified gravitational equation for dark matter is solved. The analytic…

General Relativity and Quantum Cosmology · Physics 2015-08-19 I. Brevik , V. V. Obukhov , A. V. Timoshkin

The model under consideration is the two-dimensional (2D) one-component plasma of pointlike charged particles in a uniform neutralizing background, interacting through the logarithmic Coulomb interaction. Classical equilibrium statistical…

Statistical Mechanics · Physics 2009-11-10 L. Samaj

The two-dimensional one-component plasma, i.e. the system of point-like charged particles embedded in a homogeneous neutralizing background, is studied on the surface of a cylinder of finite circumference, or equivalently in a semiperiodic…

Statistical Mechanics · Physics 2016-08-31 L. Samaj , J. Wagner , P. Kalinay

In three space dimensions, we consider the compressible inviscid model describing the time evolution of two fluids sharing the same velocity and enjoying the algebraic pressure closure. By employing the technique of convex integration, we…

Analysis of PDEs · Mathematics 2019-12-24 Yang Li , Ewelina Zatorska

Based upon the intrinsic symmetries approach to inhomogeneous cosmologies, we propose an exact solution to Einstein's field equations where the spatial sections are flat and the source is a non-perfect fluid such that the dissipative terms…

General Relativity and Quantum Cosmology · Physics 2021-03-11 E. Bittencourt , L. G. Gomes , G. B. Santos

The problem of two stiff fluids (energy density = pressure) moving radially in spherical symmetry is treated. The metric ansatz is chosen spherically symmetric, conformally static with a multiplicative separation of variables. The first…

General Relativity and Quantum Cosmology · Physics 2008-11-05 Valentin Kostov

The separate universe technique provides a means of establishing consistency relations between short wavelength observables and the long wavelength matter density fluctuations within which they evolve by absorbing the latter into the…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-13 Wayne Hu , Chi-Ting Chiang , Yin Li , Marilena LoVerde

We consider a cosmology in which a spherically symmetric large scale inhomogeneous enhancement or a void are described by an inhomogeneous metric and Einstein's gravitational equations. For a flat matter dominated universe the inhomogeneous…

Astrophysics · Physics 2008-11-26 J. W. Moffat

We revisit the global dynamics of unified dark matter cosmological models and analyze it in a new dynamical system setting. In particular, by defining a suitable set of variables we obtain a bounded variable space, a feature that allows a…

General Relativity and Quantum Cosmology · Physics 2017-02-28 Giovanni Acquaviva , Georgios Lukes-Gerakopoulos

A variety of conditions is considered under which the cosmic dark fluid may be able to develop a future Big Rip or Little Rip singularity. Both one-component and two-component models are considered. In the last-mentioned case we present a…

General Relativity and Quantum Cosmology · Physics 2012-09-25 I. Brevik , R. Myrzakulov , S. Nojiri , S. D. Odintsov

We consider a model of a binary mixture of two immiscible compressible fluids. We propose a numerical scheme and discuss its basic properties: Stability, consistency, convergence. The convergence is established via the method of generalized…

Analysis of PDEs · Mathematics 2022-02-02 Eduard Feireisl , Madalina Petcu , Bangwei She

We consider the cosmological model which allows to describe on equal footing the evolution of matter in the universe on the time interval from the inflation till the domination of dark energy. The matter is considered as a two-component…

General Relativity and Quantum Cosmology · Physics 2013-11-22 V. E. Kuzmichev , V. V. Kuzmichev

In the following we study the qualitative properties of solutions to the geodesic flow induced by a higher order two-component Camassa-Holm system. In particular, criteria to ensure the existence of temporally global solutions are…

Analysis of PDEs · Mathematics 2015-08-28 Joachim Escher , Tony Lyons

In this paper a new primal-dual mixed finite element method is introduced, aimed to model multiscale problems with several geometric subregions in the domain of interest. In each of these regions porous media fluid flow takes place, but…

Numerical Analysis · Mathematics 2020-08-21 Fernando A Morales

We investigate the structure of dynamics of large self-gravitating astrophysical systems using a self-interacting two-component model. We consider two cases, galaxy clusters and cosmic walls, for illustrations. In both cases stability…

Astrophysics · Physics 2008-11-14 Kinwah Wu , Ziri Younsi , Curtis J. Saxton

Flat and open universe models are considered, containing a mixture of cold matter (dust) and radiation interacting only through gravity, with the aim of studying their stability with respect to linear scalar perturbations. To this end the…

Astrophysics · Physics 2015-06-24 Marco Bruni , Kamilla Piotrkowska

The evolution of two isothermal, incompressible, immiscible fluids in a bounded domain is governed by Cahn-Hilliard-Navier-Stokes equations (CHNS System). In this work, we study the well-posedness results for the CHNS system with…

Analysis of PDEs · Mathematics 2025-10-28 Manika Bag , Tania Biswas , Sheetal Dharmatti

In [arXiv:1004.2488], Baumann et al. present a new formalism for studying cosmological systems where the characteristic scale of non-linearities is much smaller than the Hubble scale. By integrating out the short-wavelength modes, it is…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-08 Hyeyoun Chung

We study two-fluid systems with nonzero fluid velocities and compute their sound modes, which indicate various instabilities. For the case of two zero-temperature superfluids we employ a microscopic field-theoretical model of two coupled…

High Energy Physics - Phenomenology · Physics 2016-01-26 Alexander Haber , Andreas Schmitt , Stephan Stetina

In this paper we study global existence of weak solutions for the Quantum Hydrodynamics System in 2-D in the space of energy. We do not require any additional regularity and/or smallness assumptions on the initial data. Our approach…

Analysis of PDEs · Mathematics 2015-05-20 Paolo Antonelli , Pierangelo Marcati