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Related papers: Hamiltonian hydrodynamics of eccentric discs

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The nolinear hydrodynamic equations of the surface of a liquid drop are shown to be directly connected to Korteweg de Vries (KdV, MKdV) systems, giving traveling solutions that are cnoidal waves. They generate multiscale patterns ranging…

Fluid Dynamics · Physics 2009-11-06 Andrei Ludu , Jerry P. Draayer

We revisit the two body problem, where one body can be deformed under the action of tides raised by the companion. Tidal deformation and consequent dissipation result in spin and orbital evolution of the system. In general, the equations of…

Earth and Planetary Astrophysics · Physics 2023-06-07 Alexandre C. M. Correia , Ema F. S. Valente

The Hamiltonian structures of the incompressible ideal fluid, including entropy advection, and magnetohydrodynamics are investigated by making use of Dirac's theory of constrained Hamiltonian systems. A Dirac bracket for these systems is…

Plasma Physics · Physics 2015-06-03 Cristel Chandre , Philip J. Morrison , Emanuele Tassi

Hamilton's principle plays a central role in fluid mechanics as a fundamental tool for deriving governing equations, analyzing conservation laws, and designing structure-preserving numerical schemes. However, its classical formulation is…

Mathematical Physics · Physics 2026-04-23 François Gay-Balmaz , Cheng Yang

We derive the Hydrodynamics for a system of N active, spherical, underdamped particles, interacting through conservative forces. At the microscopic level, we represent the evolution of the particles in terms of the Kramers equation for the…

Statistical Mechanics · Physics 2022-03-15 Umberto Marini Bettolo Marconi , Andrea Puglisi , Lorenzo Caprini

We present a Hamiltonian approach for the wellknown Eigen model of the Darwin selection dynamics. Hamiltonization is carried out by means of the embedding of the population variable space, describing behavior of the system, into the space…

Biological Physics · Physics 2009-10-30 A. V. Shapovalov , E. V. Evdokimov

Many equations that arise in a physical context can be posed in the form of a Hamiltonian system, meaning that there is a symplectic structure on an appropriate phase space, and a Hamiltonian functional with respect to which time evolution…

Analysis of PDEs · Mathematics 2017-01-18 Walter Craig

We describe the long-term evolution of compact systems of terrestrial planets, using a set of simulations that match the statistical properties of the observed exoplanet distribution. The evolution is driven by tidal dissipation in the…

Earth and Planetary Astrophysics · Physics 2015-06-19 Bradley M. S. Hansen , Norman Murray

Origin of turbulence in cold accretion disks, particularly in 3D, which is expected to be hydrodynamic but not magnetohydrodynamic, is a big puzzle. While the flow must exhibit some turbulence in support of the transfer of mass inward and…

Astrophysics · Physics 2016-11-15 Banibrata Mukhopadhyay

In the variational principle leading to the Euler equation for a perfect fluid, we can use the method of undetermined multiplier for holonomic constraints representing mass conservation and adiabatic condition. For a dissipative fluid, the…

Fluid Dynamics · Physics 2012-06-03 Hiroki Fukagawa , Youhei Fujitani

A Hamiltonian dynamics is defined for the XY model by adding a kinetic energy term. Thermodynamical properties (total energy, magnetization, vorticity) derived from microcanonical simulations of this model are found to be in agreement with…

Statistical Mechanics · Physics 2014-10-13 Xavier Leoncini , Alberto D. Verga , Stefano Ruffo

Debris disks should not be completely gas-free, since there is second generation gas from outgassing of planetesimals and dust grains via sublimation, photodesorption, or collisions, generating a system of dust-to-gas ratio close to unity,…

Earth and Planetary Astrophysics · Physics 2013-08-23 Wladimir Lyra , Marc J. Kuchner

Incompressible, inviscid, irrotational, and unsteady flows with circulation $\Gamma$ around a distorted toroidal bubble are considered. A general variational principle that determines the evolution of the bubble shape is formulated. For a…

Fluid Dynamics · Physics 2009-11-10 V. P. Ruban , J. J. Rasmussen

The local axisymmetric stability of hydrodynamical and magnetized, nearly-Keplerian gaseous accretion disks around non-rotating black holes is examined in the vicinity of the classical marginally-stable orbit (at radii ~ R_ms). An…

Astrophysics · Physics 2011-05-10 Kristen Menou

We formulate the collisionless Boltzmann equation (CBE) for dense star clusters that lie within the radius of influence of a massive black hole in galactic nuclei. Our approach to these nearly Keplerian systems follows that of Sridhar and…

Astrophysics of Galaxies · Physics 2015-05-30 Jihad R. Touma , S. Sridhar

Hydrodynamic equations for a one-component plasma are derived as a generalization of the Euler equations to include the effects of the long-range Coulomb interaction. By using a variational principle, these equations self-consistently unify…

Plasma Physics · Physics 2024-03-20 Daniels Krimans , Seth Putterman

We extensively develop a perturbation theory for nonlinear cosmological dynamics, based on the Lagrangian description of hydrodynamics. We solve hydrodynamic equations for a self-gravitating fluid with pressure, given by a polytropic…

Astrophysics · Physics 2009-11-07 Takayuki Tatekawa , Momoko Suda , Kei-ichi Maeda , Masaaki Morita , Hiroki Anzai

We investigate the orbital evolution of a system of N mutually interacting stars on initially circular orbits around the dominating central mass. We include perturbative influence of a distant axisymmetric source and an extended spherical…

Astrophysics of Galaxies · Physics 2015-05-28 Jaroslav Haas , Ladislav Subr , David Vokrouhlicky

In high-quality conductors, the hydrodynamic regime of electron transport has been recently realized. In this work we theoretically investigate magnetotransport of a viscous electron fluid in samples with electron-impermeable obstacles. We…

Mesoscale and Nanoscale Physics · Physics 2023-08-01 P. S. Alekseev , A. P. Dmitriev

The standard equilibrium for radiation-dominated accretion disks has long been known to be viscously, thermally, and convectively unstable, but the nonlinear development of these instabilities---hence the actual state of such disks---has…

Astrophysics · Physics 2009-11-06 Eric Agol , Julian Krolik , Neal Turner , James Stone