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We develop our recently proposed lattice-Boltzmann method for the non-equilibrium dynamics of amphiphilic fluids (Chen, Boghosian, Coveney and Nekovee, Proc. Roy. Soc. London A, 456, 1431 (2000).) Our method maintains an orientational…

Soft Condensed Matter · Physics 2009-10-31 Maziar Nekovee , Peter V. Coveney , Hudong Chen , Bruce M. Boghosian

This work investigates a quantum system described by a Hamiltonian operator in a two dimensional noncommutative space. The system consists of an electron subjected to a perpendicular magnetic field $\mathbf{B}$, coupled to a harmonic…

Quantum Physics · Physics 2025-11-27 Bienvenu Gnim Adewi , Isiaka Aremua

We consider the interaction of a compressible fluid with a flexible plate in two space dimensions. The fluid is described by the Navier--Stokes equations in a domain that is changing in accordance with the motion of the structure. The…

Analysis of PDEs · Mathematics 2024-11-05 Dominic Breit , Arnab Roy

We present a numerical study of a model of pattern formation following a convective instability in a non-Boussinesq fluid. It is shown that many of the features observed in convection experiments conducted on $CO_{2}$ gas can be reproduced…

Condensed Matter · Physics 2009-10-22 Hao-wen Xi , Jorge Vinals , J. D. Gunton

The equations of motion for $N$ non-relativistic particles attracting according to Newton's law are shown to correspond to the equations for null geodesics in a $(3N+2)$-dimensional Lorentzian, Ricci-flat, spacetime with a covariantly…

High Energy Physics - Theory · Physics 2009-07-09 C. Duval , G. Gibbons , P. Horvathy

The dynamical evolution of collisionless particles in an expanding background is described. After discussing qualitatively the key features, the gravitational clustering of collisionless particles in an expanding universe is modelled using…

Astrophysics · Physics 2007-05-23 T. Padmanabhan

We study the transfer of cosmological perturbations through a nonsingular cosmological bounce in a special model in which the parameters of the bounce and the equation of state of matter are chosen such as to allow for an exact calculation…

High Energy Physics - Theory · Physics 2008-07-30 Stephon Alexander , Tirthabir Biswas , Robert H. Brandenberger

This paper is a continuation of the works in \cite{Euler} and \cite{NS}, where the authors have established the global existence of smooth compressible flows in infinitely expanding balls for inviscid gases and viscid gases, respectively.…

Analysis of PDEs · Mathematics 2017-06-06 Huicheng Yin , Wenbin Zhao

We consider compressible fluid flow on an evolving surface with a piecewise Lipschitz-continuous boundary from an energetic point of view. We employ both an energetic variational approach and the first law of thermodynamics to make a…

Mathematical Physics · Physics 2022-12-20 Hajime Koba

From a classical analysis, it is shown that the nondiffractive accelerating gravitational Airy wave packets are solutions of Einstein equations for their linearized tensor modes in a Friedmann-Lema\^itre-Robertson-Walker cosmological…

General Relativity and Quantum Cosmology · Physics 2025-06-25 Claudio Aravena-Plaza , Víctor Muñoz , Felipe A. Asenjo

A systematic asymptotic expansion is developed for the gravitational wave degrees of freedom of a class of expanding, vacuum Gowdy cosmological spacetimes. In the wave map description of these models, the evolution of the gravitational wave…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Beverly K. Berger

Particles interacting with a prescribed quasimonochromatic gravitational wave (GW) exhibit secular (average) nonlinear dynamics that can be described by Hamilton's equations. We derive the Hamiltonian of this "ponderomotive" dynamics to the…

General Relativity and Quantum Cosmology · Physics 2020-09-16 Deepen Garg , I. Y. Dodin

We introduce a model of noncommutative geometry that gives rise to the uncertainty relations recently derived from the discussion of a quantum clock. We investigate the dynamics of a free particle in this model from the point of view of…

High Energy Physics - Theory · Physics 2019-01-07 S. Mignemi , N. Uras

A theory of electromagnetic wave propagation in a weakly anisotropic smoothly inhomogeneous medium is developed, based on the quantum-mechanical diagonalization procedure applied to Maxwell equations. The equations of motion for the…

Optics · Physics 2008-11-26 K. Yu. Bliokh , D. Yu. Frolov , Yu. A. Kravtsov

In this article we perform dynamical analysis of a broad class of barotropic fluids in the spatially curved Friedmann-Robertson-Walker (FRW) spacetime background without considering the cosmological constant. The first part of our study…

General Relativity and Quantum Cosmology · Physics 2020-03-04 Morteza Kerachian , Giovanni Acquaviva , Georgios Lukes-Gerakopoulos

We investigate the dynamics of test particles undergoing friction forces in a Friedmann-Robertson-Walker (FRW) spacetime. The interaction with the background fluid is modeled by introducing a Poynting-Robertson-like friction force in the…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Donato Bini , Andrea Geralico , Daniele Gregoris , Sauro Succi

We analyze the global nonlinear stability of FRW (Friedmann-Robertson-Walker) spacetimes in presence of an irrotational perfect fluid. We assume that the fluid is governed by the so-called (generalized) Chaplygin equation of state relating…

General Relativity and Quantum Cosmology · Physics 2015-12-14 Philippe G. LeFloch , Changhua Wei

We consider the stationary state of a fluid comprised of inelastic hard spheres or disks under the influence of a random, momentum-conserving external force. Starting from the microscopic description of the dynamics, we derive a nonlinear…

Statistical Mechanics · Physics 2013-02-25 W. T. Kranz , M. Sperl , A. Zippelius

We study holographic three-dimensional fluids with vorticity in local equilibrium and discuss their relevance to analogue gravity systems. The Fefferman-Graham expansion leads to the fluid's description in terms of a comoving and rotating…

High Energy Physics - Theory · Physics 2015-06-05 Robert G. Leigh , Anastasios C. Petkou , P. Marios Petropoulos

A modelling methodology to reproduce the experimental measurements of a turbulent flow under the presence of symmetry is presented. The flow is a three-dimensional wake generated by an axisymmetric body. We show that the dynamics of the…

Fluid Dynamics · Physics 2023-07-19 G. Rigas , A. S. Morgans , R. D. Brackston , J. F. Morrison