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We present an algorithm for systematically reconstructing a solution of the (d+2)-dimensional vacuum Einstein equations from a (d+1)-dimensional fluid, extending the non-relativistic hydrodynamic expansion of Bredberg et al in…

High Energy Physics - Theory · Physics 2012-04-04 Geoffrey Compère , Paul McFadden , Kostas Skenderis , Marika Taylor

The space of the solutions of the differential equations resulting from considering matter fluids of scalar field type or perfect fluid in Einstein-aether theory is analyzed. The Einstein-aether theory of gravity consists of General…

General Relativity and Quantum Cosmology · Physics 2020-06-16 Alfredo Millano

On the basis of gauge principle in the field theory, a new variational formulation is presented for flows of an ideal fluid. The fluid is defined thermodynamically by mass density and entropy density, and its flow fields are characterized…

Chaotic Dynamics · Physics 2007-10-12 Tsutomu Kambe

We investigate anisotropic fluid cosmology in a situation where the spacetime metric back-reacts in a local, time-dependent way to the presence of inhomogeneities. We derive exact solutions to the Einstein field equations describing…

General Relativity and Quantum Cosmology · Physics 2021-08-25 Mariano Cadoni , Andrea P. Sanna

We investigate the bounce cosmology induced by inhomogeneous viscous fluids in FRW space-time (non necessarly flat), taking into account the early-time acceleration after the bounce. Different forms for the scale factor and several examples…

General Relativity and Quantum Cosmology · Physics 2015-09-21 Ratbay Myrzakulov , Lorenzo Sebastiani

Einstein's equations for a Robertson-Walker fluid source endowed with rotation Einstein's equations for a Robertson-Walker fluid source endowed with rotation are presented upto and including quadratic terms in angular velocity parameter. A…

General Relativity and Quantum Cosmology · Physics 2015-06-25 R J Wiltshire

Motivated by the gravity/fluid correspondence, we introduce a new method for characterizing nonlinear gravitational interactions. Namely we map the nonlinear perturbative form of the Einstein equation to the equations of motion of a…

General Relativity and Quantum Cosmology · Physics 2015-04-16 Huan Yang , Fan Zhang , Stephen R. Green , Luis Lehner

This article considers non-stationary incompressible linear fluid equations in a moving domain. We demonstrate the existence and uniqueness of an appropriate weak formulation of the problem by making use of the theory of time-dependent…

Analysis of PDEs · Mathematics 2023-10-26 Ana Djurdjevac , Carsten Gräser , Philip J. Herbert

We present a space-time continuous-Galerkin finite element method for solving incompressible Navier-Stokes equations. To ensure stability of the discrete variational problem, we apply ideas from the variational multi-scale method. The…

Numerical Analysis · Mathematics 2024-11-25 Biswajit Khara , Robert Dyja , Kumar Saurabh , Anupam Sharma , Baskar Ganapathysubramanian

We study the finite element formulation of general boundary conditions for incompressible flow problems. Distinguishing between the contributions from the inviscid and viscid parts of the equations, we use Nitsche's method to develop a…

Numerical Analysis · Mathematics 2023-07-19 Roland Becker , Daniela Capatina , Robert Luce , David Trujillo

We analyze the Navier Stokes equation, and show that all non-viscous, irrotational flows are barotropic. As far as we know, this has never been stated in the literature before, and indirectly suggests that vorticity is required to make…

Fluid Dynamics · Physics 2021-08-16 Steven Nerney , Edward G. Nerney

The long-time existence and umbilicity estimates for compact, graphical solutions to expanding curvature flows are deduced in Riemannian warped products of a real interval with a compact fibre. Notably we do not assume the ambient manifold…

Differential Geometry · Mathematics 2019-02-14 Julian Scheuer

We construct models of static spherical distributions of perfect fluid in trace--free Einstein gravity theory. The equations governing the gravitational field are equivalent to the standard Einstein's equations however, their presentation…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Sudan Hansraj , Rituparno Goswami , George Ellis , Njabulo Mkhize

We develop a simple model to study classical fields on the background of a fluctuating spacetime volume. It is applied to formulate the stochastic Einstein equations with a perfect-fluid source. We investigate the particular case of a…

General Relativity and Quantum Cosmology · Physics 2017-09-06 Vladimir Dzhunushaliev , Hernando Quevedo

The recent introduction of the gradient flow has provided a new tool to probe the dynamics of quantum field theories. The latest developments have shown how to use the gradient flow for the exploration of symmetries, and the definition of…

High Energy Physics - Theory · Physics 2015-06-16 Luigi Del Debbio , Agostino Patella , Antonio Rago

We consider Bianchi VI spacetime, which also can be reduced to Bianchi types VI0-V-III-I. We initially consider the most general form of the energy-momentum tensor which yields anisotropic stress and heat flow. We then derive an…

General Relativity and Quantum Cosmology · Physics 2011-08-26 Ozgur Akarsu , Can B. Kilinc

The full set of equations governing the structure and the evolution of self--gravitating cylindrically symmetric dissipative fluids with anisotropic stresses, is written down in terms of scalar quantities obtained from the orthogonal…

General Relativity and Quantum Cosmology · Physics 2012-09-11 L. Herrera , A. Di Prisco J. Ospino

We review the Analogue Gravity description of a unidirectional water wave system, assuming no prior knowledge of General Relativity or differential geometry. In so doing, we generalize established results concerning an effective curved…

General Relativity and Quantum Cosmology · Physics 2026-03-09 Alessia Biondi , Scott Robertson , Germain Rousseaux

This work aims to introduce a heuristic timestep-adaptive algorithm for Computational Fluid Dynamics (CFD) and Fluid-Structure Interaction (FSI) problems where the flow is dominated by the pressure. In such scenarios, many time-adaptive…

Numerical Analysis · Mathematics 2024-07-02 Ivan Prusak , Davide Torlo , Monica Nonino , Gianluigi Rozza

The equations for a self-similar solution of an inviscid incompressible fluid are mapped into an integral equation which hopefully can be solved by iteration. It is argued that the exponent of the similarity are ruled by Kelvin's theorem of…

Fluid Dynamics · Physics 2016-11-22 Yves Pomeau