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We develop, and implement in a Finite Volume environment, a density-based approach for the Euler equations written in conservative form using density, momentum, and total energy as variables. Under simplifying assumptions, these equations…

Numerical Analysis · Mathematics 2024-05-01 Nicola Clinco , Michele Girfoglio , Annalisa Quaini , Gianluigi Rozza

We introduce a formulation of Eulerian general relativistic hydrodynamics which is applicable for (perfect) fluid data prescribed on either spacelike or null hypersurfaces. Simple explicit expressions for the characteristic speeds and…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Philippos Papadopoulos , Jose A. Font

The method of non-Riemannian (metric-independent) spacetime volume-forms (alternative generally-covariant integration measure densities) is applied to construct a modified model of gravity coupled to a single scalar field providing an…

General Relativity and Quantum Cosmology · Physics 2017-08-01 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

We introduce a finite volume scheme to solve a special case of isotropic 3-wave kinetic equations. We test our numerical solution against theoretical results concerning the long time behavior of the energy and observe that our solutions…

Numerical Analysis · Mathematics 2023-06-16 Steven Walton , Minh-Binh Tran

We consider an isothermal compressible fluid evolving on a cosmological background which may be either expanding or contracting toward the future. The Euler equations governing such a flow consist of two nonlinear hyperbolic balance laws…

Analysis of PDEs · Mathematics 2022-10-12 Yangyang Cao , Mohammad A. Ghazizadeh , Philippe G. LeFloch

This work concerns the numerical approximation with a finite volume method of inviscid, nonequilibrium, high-temperature flows in multiple space dimensions. It is devoted to the analysis of the numerical scheme for the approximation of the…

Numerical Analysis · Mathematics 2021-03-08 Claude Marmignon , Fabio Naddei , Florent Renac

Considering the isentropic Euler equations of compressible fluid dynamics with geometric effects included, we establish the existence of entropy solutions for a large class of initial data. We cover fluid flows in a nozzle or in spherical…

Analysis of PDEs · Mathematics 2008-12-16 Philippe G. LeFloch , Michael Westdickenberg

The effective evolution of an inhomogeneous universe model in any theory of gravitation may be described in terms of spatially averaged variables. In Einstein's theory, restricting attention to scalar variables, this evolution can be…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Thomas Buchert

This paper considers one-dimensional equations of acoustics equations of inhomogeneous media and the system of gas dynamics equations with constant entropy. Using the Riemann approach, the gas dynamics equations are reduced to a…

Mathematical Physics · Physics 2025-06-12 O. V. Kaptsov

As a first step towards the numerical analysis of the stochastic primitive equations of the atmosphere and oceans, we study their time discretization by an implicit Euler scheme. From deterministic viewpoint the 3D Primitive Equations are…

Analysis of PDEs · Mathematics 2014-04-14 Nathan Glatt-Holtz , Roger Temam , Chuntian Wang

Centered numerical fluxes can be constructed for compressible Euler equations which preserve kinetic energy in the semi-discrete finite volume scheme. The essential feature is that the momentum flux should be of the form $f^m_\jph =…

Numerical Analysis · Computer Science 2016-08-24 Praveen Chandrashekar

We consider the relativistic Euler equations governing spherically symmetric, perfect fluid flows on the outer domain of communication of Schwarzschild spacetime, and we introduce a version of the finite volume method which is formulated…

General Relativity and Quantum Cosmology · Physics 2013-01-01 Philippe G. LeFloch , Hasan Makhlof

We present the first cosmological simulations that consistently include nonlinear clustering dark energy evolved as a fluid with the numerical hydrodynamics code Nefertiti. Dark energy perturbations become fully nonlinear on small scales,…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Linda Blot , Théo Gayoux , Fabian Schmidt , Pier Stefano Corasaniti , Bastien de Ligondes

We investigate the possibility of using cosmological observations to probe and constrain an imperfect dark energy fluid. We consider a general parameterization of the dark energy component accounting for an equation of state, speed of sound…

Astrophysics · Physics 2008-12-18 D. F. Mota , J. R. Kristiansen , T. Koivisto , N. E. Groeneboom

The geometric nature of Euler fluids has been clearly identified and extensively studied over the years, culminating with Lagrangian and Hamiltonian descriptions of fluid dynamics where the configuration space is defined as the…

Dynamical Systems · Mathematics 2015-03-13 Dmitry Pavlov , Patrick Mullen , Yiying Tong , Eva Kanso , Jerrold E. Marsden , Mathieu Desbrun

The method of non-Riemannian volume-forms (metric-independent covariant integration measure densities on the spacetime manifold) is applied to construct a unified model of dynamical dark energy plus dark matter as a dust fluid resulting…

General Relativity and Quantum Cosmology · Physics 2020-03-26 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

We review the hydrodynamics of the dark sector components in Cosmology. For this purpose we use the approach of Newtonian gravitational instability, and thereafter we add corrections to arrive to a full relativistic description. In…

Numerical hydrodynamical simulations have proven a successful means of reproducing many of the statistical properties of the Lyman-Alpha forest as measured in high redshift quasar spectra. Pseudo-hydrodynamical methods based only on…

Astrophysics · Physics 2009-08-18 A. Meiksin , M. White

The fluid flow transport and hydrodynamic problems often take the form of hyperbolic systems of conservation laws. In this work we will present a new scheme of finite volume methods for solving these evolution equations. It is a family of…

Numerical Analysis · Mathematics 2021-05-25 Moussa Ziggaf , Mohamed Boubekeur , Imad kissami , Fayssal Benkhaldoun , Imad El Mahi

We propose high-order well-balanced finite-volume schemes for a broad class of hydrodynamic systems with attractive-repulsive interaction forces and linear and nonlinear damping. Our schemes are suitable for free energies containing…

Numerical Analysis · Mathematics 2020-11-20 José A. Carrillo , Manuel J. Castro , Serafim Kalliadasis , Sergio P. Perez
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