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

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We study the baryon mass fraction in a set of hydrodynamical simulations of galaxy clusters performed using the Tree+SPH code GADGET-2. We investigate the dependence of the baryon fraction upon the radiative cooling, star formation,…

Astrophysics · Physics 2009-11-13 S. Ettori , K. Dolag , S. Borgani , G. Murante

We present results from the first high-resolution hydrodynamical simulations of non-Gaussian cosmological models. We focus on the statistical properties of the transmitted Lyman-alpha flux in the high redshift intergalactic medium. Imprints…

Astrophysics · Physics 2010-03-26 M. Viel , E. Branchini , K. Dolag , M. Grossi , S. Matarrese , L. Moscardini

We develop an analytic model of intermittent, three-dimensional, strong, reduced magnetohydrodynamic turbulence with zero cross helicity. We take the fluctuation amplitudes to have a log-Poisson distribution and incorporate into the model a…

Solar and Stellar Astrophysics · Physics 2014-03-26 Benjamin D. G. Chandran , Alexander A. Schekochihin , Alfred Mallet

A Lagrangian relativistic approach to the non--linear dynamics of cosmological perturbations of an irrotational collisionless fluid is considered. Solutions are given at second order in perturbation theory for the relevant fluid and…

Astrophysics · Physics 2015-06-24 S. Matarrese , O. Pantano , D. Saez

Nonlinear gravitational instability is a crucial way to comprehend the clustering of matter and the formation of nonlinear structures in both the Universe and stellar systems. However, with the exception of a few exact particular solutions…

General Relativity and Quantum Cosmology · Physics 2023-07-10 Chao Liu

We develop an analysis pipeline for characterizing the topology of large scale structure and extracting cosmological constraints based on persistent homology. Persistent homology is a technique from topological data analysis that quantifies…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-14 Matteo Biagetti , Alex Cole , Gary Shiu

We study a diffuse interface model for the flow of two viscous incompressible Newtonian fluids in a bounded domain. The fluids are assumed to be macroscopically immiscible, but a partial mixing in a small interfacial region is assumed in…

Analysis of PDEs · Mathematics 2011-04-01 Helmut Abels

The dynamic evolution of the baryonic intergalactic medium (IGM) caused by the underlying dark matter gravity is governed by the Navier-Stokes equations in which many cooling and heating processes are involved. However, it has long been…

Astrophysics · Physics 2016-08-30 Bryan Kim , Ping He , Jesús Pando , Long-Long Feng , Li-Zhi Fang

The evolution of the interface separating a conduit of light, viscous fluid rising buoyantly through a heavy, more viscous, exterior fluid at small Reynolds numbers is governed by the interplay between nonlinearity and dispersion. Previous…

Fluid Dynamics · Physics 2015-06-16 Nicholas K. Lowman , Mark A. Hoefer

We analyze multi-field inflationary systems which yield strongly scale dependent non-Gaussianity with a shape that is very close to the local shape. As in usual multi-field models, the non-Gaussianity arises from the non-linear transfer of…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-27 Jason Kumar , Louis Leblond , Arvind Rajaraman

According to the classical theory of Brownian motion, the mean squared displacement of diffusing particles evolves linearly with time whereas the distribution of their displacements is Gaussian. However, recent experiments on mesoscopic…

Soft Condensed Matter · Physics 2021-08-24 J. M. Miotto , S. Pigolotti , A. V. Chechkin , S. Roldán-Vargas

Through asymptotic expansion, the large-time behavior of incompressible Navier--Stokes flow in $n$-dimensional whole space is depicted. Especially, from their parabolic scalings, large-time behaviors of any terms on the expansion are…

Analysis of PDEs · Mathematics 2025-05-07 Masakazu Yamamoto

We analyze hierarchical structure formation based on scale-free initial conditions in an Einstein-de Sitter universe, including a baryonic component. We present three independent, smoothed particle hydrodynamics (SPH) simulations, performed…

Astrophysics · Physics 2009-10-30 J. Michael Owen , David H. Weinberg , August E. Evrard , Lars Hernquist , Neal Katz

Recent progress has revealed a number of constraints that cosmological correlators and the closely related field-theoretic wavefunction must obey as a consequence of unitarity, locality, causality and the choice of initial state. When…

High Energy Physics - Theory · Physics 2024-03-20 Carlos Duaso Pueyo , Enrico Pajer

The probability density function (PDF) of the logarithmic density contrast, $s=\ln (\rho/\rho_0)$, with gas density $\rho$ and mean density $\rho_0$, for hydrodynamical supersonic turbulence is well-known to have significant non-Gaussian…

Astrophysics of Galaxies · Physics 2022-11-16 James R. Beattie , Philip Mocz , Christoph Federrath , Ralf S. Klessen

We investigate the relationship between the dark matter and baryons in the linear regime. This relation is quantified by the so-called ``filtering scale''. We show that a simple gaussian ansatz which uses the filtering scale provides a good…

Unified dark matter cosmologies economically combine missing matter and energy in a single fluid. Of these models, the standard Chaplygin gas is theoretically motivated, but faces problems in explaining large scale structure if linear…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Abdelrahman Abdullah , Amr El-Zant , Ali Ellithi

This paper investigates the Cauchy problem for the compressible pressureless Navier-Stokes system in $\mathbb{R}^d$ with $d \geq 2$. Unlike the standard isentropic compressible Navier-Stokes system, the density in the pressureless model…

Analysis of PDEs · Mathematics 2025-11-05 Fucai Li , Jinkai Ni , Zhipeng Zhang

We present a new high-order accurate computational fluid dynamics model based on the incompressible Navier-Stokes equations with a free surface for the accurate simulation of nonlinear and dispersive water waves in the time domain. The…

Numerical Analysis · Mathematics 2024-06-06 Anders Melander , Max E. Bitsch , Dong Chen , Allan P. Engsig-Karup

The theory of dark matter superfluidity has emerged as a compelling framework, in which the dynamics are governed by a non-relativistic $P(X)$ superfluid Lagrangian that naturally leads to Modified Newtonian Dynamics (MOND)-like behavior…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Seturumane Tema