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Related papers: Remarks on the Einstein-Euler-Entropy system

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We consider the 3D compressible isentropic Euler equations describing the motion of a liquid in an unbounded initial domain with a moving boundary and a fixed flat bottom at finite depth. The liquid is under the influence of gravity and…

Analysis of PDEs · Mathematics 2026-05-08 Chenyun Luo , Junyan Zhang

We find the Euler-Lagrangian equation by maximising the total entropy. Hence we obtain an expression for mass of the spherically symmetric system by solving the Euler-Lagrangian equation where the Homotopy Perturbation Method has been…

General Physics · Physics 2017-12-05 Abdul Aziz , Sourav Roy Chowdhury , Debabrata Deb , Farook Rahaman , Saibal Ray , B. K. Guha

In the field of differential equations, particularly fluid dynamics, many researchers have shown an interest in the behavior of time periodic solutions. In this paper, we study isentropic gas flow in a bounded interval and apply a time…

Analysis of PDEs · Mathematics 2023-03-17 Naoki Tsuge

Two recent articles \cite{ashtekar2015general, moncrief2019could} suggested an interesting dynamical mechanism within the framework of the vacuum Einstein flow (or Einstein-$\Lambda$ flow if a positive cosmological constant $\Lambda$ is…

General Relativity and Quantum Cosmology · Physics 2022-03-23 Vincent Moncrief , Puskar Mondal

We consider the Cauchy problem for the isentropic compressible Euler equations in a three-dimensional periodic domain under general pressure laws. For any smooth initial density away from the vacuum, we construct infinitely many entropy…

Analysis of PDEs · Mathematics 2022-07-13 Vikram Giri , Hyunju Kwon

By refining the method proposed in arXiv:2010.07660, entropy current and entropy density for a relativistic hydrostatic equilibrium system with spherical symmetry are constructed as a non-Noether conserved charge in the Einstein gravity…

General Relativity and Quantum Cosmology · Physics 2024-07-12 Shuichi Yokoyama

In this paper we study the existence of solutions to a steady system that describes the motion of a micropolar electrorheological fluid. The constitutive relations for the stress tensors belong to the class of generalized Newtonian fluids.…

Analysis of PDEs · Mathematics 2021-12-16 Alex Kaltenbach , Michael Růžička

In this paper, we study the coupled Einstein constraint equations on complete manifolds through the conformal method, focusing on non-compact manifolds with flexible asymptotics. This is physically well-motivated by standard cosmological…

Analysis of PDEs · Mathematics 2026-03-25 Rodrigo Avalos , Jorge Lira , Nicolas Marque

We derive the spin Euler equation for ideal flows by applying the spherical Clebsch mapping. This equation is based on the spin vector rather than the velocity. It enables a feasible Lagrangian study of fluid dynamics, as the isosurface of…

Fluid Dynamics · Physics 2024-04-25 Zhaoyuan Meng , Yue Yang

In this paper we study the well-posedness in Sobolev spaces of the incompressible Euler equations in an infinite strip delimited from below by a non-flat bottom and from above by a free-surface. We allow the presence of vorticity and…

Analysis of PDEs · Mathematics 2025-07-22 Théo Fradin

We study the compressible Euler equations in the isentropic nozzle flow. The global existence of an $L^{\infty}$ solution has been proved in (Tsuge in Nonlinear Anal. Real World Appl. 209: 217-238 (2017)) for large data and general nozzle.…

Analysis of PDEs · Mathematics 2019-08-12 Naoki Tsuge

We show that in one space dimension Lipschitz solutions of extremal surface equations are equivalent to entropy solutions in $L^\infty(\R)$ of a non-strictly hyperbolic system of conservation laws. We obtain an explicit representation…

Mathematical Physics · Physics 2015-05-20 Yue-Jun Peng , Yong-Fu Yang

We consider the Cauchy problem for the barotropic Euler system coupled to Helmholtz or Poisson equations, in the whole space. We assume that the initial density is small enough, and that the initial velocity is close to some reference…

Analysis of PDEs · Mathematics 2019-06-20 Šárka Nečasová , Xavier Blanc , Raphaël Danchin , Bernard Ducomet , andš Nečasová

For any positive integer $k$, we prove the existence of nontrivial $C^k$-smooth uniformly rotating solutions to the 2D incompressible Euler equations with compact spatial support. These solutions, which can be chosen to be small…

Analysis of PDEs · Mathematics 2025-11-18 Alberto Enciso , Antonio J. Fernández , David Ruiz

We establish a relative energy framework for the Euler-Korteweg system with non-convex energy. This allows us to prove weak-strong uniqueness and to show convergence to a Cahn-Hilliard system in the large friction limit. We also use…

Analysis of PDEs · Mathematics 2017-09-08 Jan Giesselmann , Athanasios E. Tzavaras

This paper is devoted to the analysis of the incompressible Euler equation in a time-dependent fluid domain, whose interface evolution is governed by the law of linear elasticity. Our main result asserts that the Cauchy problem is globally…

Analysis of PDEs · Mathematics 2025-04-02 Thomas Alazard , Chengyang Shao , Haocheng Yang

The Einstein-Vlasov-Fokker-Planck system describes the kinetic diffusion dynamics of self-gravitating particles within the Einstein theory of general relativity. We study the Cauchy problem for spatially homogeneous and isotropic solutions…

Analysis of PDEs · Mathematics 2017-10-30 Simone Calogero , Stephen Pankavich

The structure of the Einstein field equations describing the gravitational collapse of spherically symmetric isotropic fluids is analyzed here for general equations of state. A suitable system of coordinates is constructed which allows us,…

General Relativity and Quantum Cosmology · Physics 2015-03-24 Roberto Giambò , Giulio Magli

In this paper, we consider an Euler-Bernoulli beam equation with time-varying internal fluid. We assume that the fluid is moving with non-constant velocity and dynamical boundary conditions are satisfied. We prove the existence and…

Analysis of PDEs · Mathematics 2021-03-17 Akram Ben Aissa , Mama Abdelli , Alessandro Duca

We consider the Cauchy problems of a non-strictly hyperbolic system which describes the compressible Euler fluid with exothermic reaction. In this paper a Lyapunov-type functional is constructed for balance laws. By analysis of the flow…

Dynamical Systems · Mathematics 2018-01-30 Kai Hu