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Related papers: Modeling the Lyman-$\alpha$ forest with Eulerian a…

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We present the first hydrodynamical simulations of structure formation using the new moving mesh code AREPO and compare the results with GADGET simulations based on a traditional smoothed particle hydrodynamics (SPH) technique. The two…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Mark Vogelsberger , Debora Sijacki , Dusan Keres , Volker Springel , Lars Hernquist

Very recently a new inversion method has been developped to analyze the intergalactic medium seen in absorption in quasar spectra (the so-called Lyman-alpha forest). This method is applied to recover the temperature of the gas and the…

The Smoothed Particles Hydrodynamics (SPH) is a particle-based, meshfree, Lagrangian method used to simulate multidimensional fluids with arbitrary geometries, most commonly employed in astrophysics, cosmology, and computational…

Computational Engineering, Finance, and Science · Computer Science 2022-12-21 Aurélien Cavelan , Rubén M. Cabezón , Michal Grabarczyk , Florina M. Ciorba

Smoothed particle hydrodynamics (SPH) is typically used for barotropic fluids, where the pressure depends only on the local mass density. Here, we show how to incorporate the entropy into the SPH, so that the pressure can also depend on the…

Fluid Dynamics · Physics 2024-06-21 Michal Pavelka , Vaclav Klika , Ondrej Kincl

We model the $\lya$ forest in a spatially flat, CDM model with $\Omega=0.4$, with an Eulerian hydrodynamic simulation, and find that the intergalactic, photoionized gas collapses into sheet-like and filamentary structures which produce…

Astrophysics · Physics 2009-10-28 Jordi Miralda-Escude , Renyue Cen , Jeremiah P. Ostriker , Michael Rauch

Hydrogen emission lines can provide extensive information about star-forming galaxies in both the local and high-redshift Universe. We present a detailed Lyman continuum (LyC), Lyman-alpha (Ly{\alpha}), and Balmer line (H{\alpha} and…

Direct numerical simulation of subsonic turbulence with smoothed particle hydrodynamics (SPH) has traditionally been hampered by zeroth-order (E0) errors, inaccurate gradient evaluations, and excessive numerical dissipation. We demonstrate…

The axisymmetric form of the hydrodynamic equations within the smoothed particle hydrodynamics (SPH) formalism is presented and checked using idealized scenarios taken from astrophysics (free fall collapse, implosion and further pulsation…

Astrophysics · Physics 2009-11-13 D. Garcia-Senz , A. Relano , R. M. Cabezon , E. Bravo

Cosmological N-Body simulations are used for a variety of applications. Indeed progress in the study of large scale structures and galaxy formation would have been very limited without this tool. For nearly twenty years the limitations…

Astrophysics · Physics 2010-05-07 J. S. Bagla , Nishikanta Khandai

On large scales, the Lyman-$\alpha$ forest provides insights into the expansion history of the Universe, while on small scales, it imposes strict constraints on the growth history, the nature of dark matter, and the sum of neutrino masses.…

In this paper we propose an accurate, and computationally efficient method for incorporating adaptive spatial resolution into weakly-compressible Smoothed Particle Hydrodynamics (SPH) schemes. Particles are adaptively split and merged in an…

Fluid Dynamics · Physics 2022-05-17 Abhinav Muta , Prabhu Ramachandran

Varieties of energy-stable numerical methods have been developed for incompressible two-phase flows based on the Navier-Stokes-Cahn-Hilliard (NSCH) model in the Eulerian framework, while few investigations have been made in the Lagrangian…

Fluid Dynamics · Physics 2023-03-22 Xiaoyu Feng , Zhonghua Qiao , Shuyu Sun , Xiuping Wang

Cosmological simulations with gas provide a detailed description of the intergalactic medium, making possible predictions of neutral hydrogen absorption in the spectra of background QSOs. We present results from a high-resolution…

Astrophysics · Physics 2009-10-28 Lars Hernquist , Neal Katz , David H. Weinberg , Jordi Miralda-Escude

We present a new 3D SPH code which solves the general relativistic field + hydrodynamics equations in the conformally flat approximation. Several test cases are considered to test different aspects of the code. We finally apply then the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Roland Oechslin , Stephan Rosswog , Friederich-Karl Thielemann

We compare simulations of the Lyman-alpha forest performed with two different hydrodynamical codes, Gadget-2 and Enzo. A comparison of the dark matter power spectrum for simulations run with identical initial conditions show differences of…

Astrophysics · Physics 2008-11-26 John A. Regan , Martin G. Haehnelt , Matteo Viel

In this paper, we present a multi-resolution smoothed particle hydrodynamics (SPH) method for modeling fluid-structure interaction (FSI) problems. By introducing different smoothing lengths and time steps, the spatio-temporal discretization…

Computational Engineering, Finance, and Science · Computer Science 2019-12-02 Chi Zhang , Massoud Rezavand , Xiangyu Hu

In recent years, forest fires and maritime accidents have occurred frequently, which have had a bad impact on human production and life. Thus, the development of seaplanes is an increasingly urgent demand. It is important to study the…

Fluid Dynamics · Physics 2023-06-22 Yang Xu , Peng-Nan Sun , Xiao-Ting Huang , Salvatore Marrone , Lei-Ming Geng

Studying the matter distribution in the universe through the Lyman-$\alpha$ forest allows us to constrain small-scale physics in the high-redshift regime. Spectroscopic quasar surveys are generating increasingly large datasets that require…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-23 Josue De-Santiago , Rafael Gutiérrez-Balboa , Gustavo Niz , Alma X. González-Morales

Particle methods play an important role in the study of a wide variety of astrophysical fluid dynamics problems. The different methods currently in use are all variants of the so-called Smoothed Particle Hydrodynamics (SPH) scheme…

Astrophysics · Physics 2009-10-31 Frederic A. Rasio

We introduce the cosmological HYPER code based on an innovative hydro-particle-mesh (HPM) algorithm for efficient and rapid simulations of gas and dark matter. For the HPM algorithm, we update the approach of Gnedin & Hui (1998) to expand…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Yizhou He , Hy Trac , Nickolay Y. Gnedin