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Related papers: Non-Gaussianity of the Cosmic Baryon Fluid: Log-Po…

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we study, in this paper, the non-Gaussian features of the mass density field of neutral hydrogen fluid and the Ly-alpha transmitted flux of QSO absorption spectrum from the point-of-view of self-similar log-Poisson hierarchy. It has been…

Astrophysics · Physics 2011-02-11 Yi Lu , Yao-Quan Chu , Li-Zhi Fang

We investigate the non-Gaussian features of the IGM at redshift $z\sim 5 - 6$ using Ly$\alpha$ transmitted flux of quasar absorption spectra and cosmological hydrodynamic simulation of the concordance $\Lambda$CDM universe. We show that the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Yi Lu , Weishan Zhu , Yaoquan Chu , Long-long Feng , Li-Zhi Fang

We investigate the statistical properties of cosmic baryon fluid in the nonlinear regime, which is crucial for understanding the large-scale structure formation of the universe. With the hydrodynamic simulation sample of the Universe in the…

Astrophysics · Physics 2009-11-11 Ping He , Jiren Liu , Long-Long Feng , Chi-Wang Shu , Li-Zhi Fang

(Abridged) The nonlinear evolution of a system consisting of baryons and dark matter is generally characterized by strong shocks and discontinuities. The baryons slow down significantly at postshock areas of gravitational strong shocks,…

Astrophysics · Physics 2009-11-10 Ping He , Long-Long Feng , Li-Zhi Fang

The dynamics of self-gravitating fluids is analyzed within the framework of a collisionless Boltzmann equation in the presence of gravitational fields and Poisson equation. Two cases are analyzed: a system with baryonic and dark matter in a…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-06 Gilberto M. Kremer

We investigate the properties of hybrid gravitational/hydrodynamical simulations, examining both the numerics and the general physical properties of gravitationally driven, hierarchical collapse in a mixed baryonic/dark matter fluid. We…

Astrophysics · Physics 2009-10-28 J. Michael Owen , Jens V. Villumsen

I compute the 3-D non-linear evolution of gas and dark matter fluids in the neighbourhood of cosmic string wakes which are formed at high redshift ($z\simeq 2240$) for a ``realistic'' scenario of wake formation. These wakes are the ones…

Astrophysics · Physics 2009-10-30 Benjamin D. Wandelt

It has been revealed recently that, in the scale free range, i.e. from the scale of the onset of nonlinear evolution to the scale of dissipation, the velocity and mass density fields of cosmic baryon fluid are extremely well described by…

Astrophysics · Physics 2009-05-16 Qiang Yuan , Hao-Yi Wan , Tong-Jie Zhang , Ji-Ren Liu , Long-Long Feng , Li-Zhi Fang

This work presents a macroscopic model for the flow of two immiscible and incompressible fluids within inhomogeneous porous media. At the pore scale, the flow is governed by the full Navier-Stokes equations while the phase interface…

Fluid Dynamics · Physics 2026-03-02 Chunhua Zhang , Peiyao Liu , Cheng Peng , Lian-Ping Wang , Zhaoli Guo

The Cauchy problem of the bipolar Navier-Stokes-Poisson system (1.1) in dimension three is considered. We obtain the pointwise estimates of the time-asymptotic shape of the solution, which exhibit generalized Huygens' principle as the…

Analysis of PDEs · Mathematics 2017-06-28 Zhigang Wu , Weike Wang

We revise the Bayesian inference steps required to analyse the cosmological large-scale structure. Here we make special emphasis in the complications which arise due to the non-Gaussian character of the galaxy and matter distribution. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Francisco-Shu Kitaura

We investigate the cosmological perturbation dynamics for a universe consisting of pressureless baryonic matter and a viscous fluid, the latter representing a unified model of the dark sector. In the homogeneous and isotropic background the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-21 W. S. Hipólito-Ricaldi , H. E. S. Velten , W. Zimdahl

For the water-air system, the bulk density ratio is as high as about 1000; no model can fully tackle such a high density ratio system. In the Navier-Stokes and Euler equations, the density $\rho$ within the water-air interface is assumed to…

Fluid Dynamics · Physics 2026-01-27 Fei Wang

In this paper we consider the incompressible inhomogeneous Navier-Stokes equations in the whole space with dimension $n\geq 3$. We present local and global well-posedness results in a new framework for inhomogeneous fluids, namely…

Analysis of PDEs · Mathematics 2023-09-04 Lucas C. F. Ferreira , Daniel F. Machado

In the standard model of cosmology, the background evolution of the Universe can in general be adequately described by general relativity and a uniform and isotropic metric minimally coupled with a collection of perfect fluids. These fluids…

General Relativity and Quantum Cosmology · Physics 2022-07-19 R. P. L. Azevedo

We consider the compressible Navier-Stokes-Poisson equations in $\mathbb{R}^d$ ($d\geq2$), a classical model for barotropic compressible flows coupled with a self-consistent electrostatic potential. We show that the electrostatic coupling…

Analysis of PDEs · Mathematics 2026-02-11 Ling-yun Shou , Zihao Song

The mean mass densities of cosmic dark matter is larger than that of baryonic matter by a factor of about 5 in the $\Lambda$CDM universe. Therefore, the gravity on large scales should be dominant by the distribution of dark matter in the…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-24 Li-Zhi Fang , Weishan Zhu

We consider the gravitational Euler-Poisson system with a linear equation of state on an expanding cosmological model of the Universe. The expansion of the spatial sections introduces an additional dissipating effect in the Euler equation.…

Analysis of PDEs · Mathematics 2025-12-23 David Fajman , Maciej Maliborski , Maximilian Ofner , Todd Oliynyk , Zoe Wyatt

We present a new prescription for analysing cosmological perturbations in a more-general class of scalar-field dark-energy models where the energy-momentum tensor has an imperfect-fluid form. This class includes Brans-Dicke models, f(R)…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-03 Ignacy Sawicki , Ippocratis D. Saltas , Luca Amendola , Martin Kunz

We investigate the long-time properties of the two-dimensional inviscid Boussinesq equations near a stably stratified Couette flow, for an initial Gevrey perturbation of size $\varepsilon$. Under the classical Miles-Howard stability…

Analysis of PDEs · Mathematics 2021-03-26 Jacob Bedrossian , Roberta Bianchini , Michele Coti Zelati , Michele Dolce
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