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Using the Post-Minkowskian formalism and considering rotation as a perturbation, we compute an approximate interior solution for a stationary perfect fluid with constant density and axial symmetry. A suitable change of coordinates allows…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. A. Cabezas , E. Ruiz

A new symplectic variational approach is developed for modeling dissipation in kinetic equations. This approach yields a double bracket structure in phase space which generates kinetic equations representing coadjoint motion under canonical…

Plasma Physics · Physics 2007-08-21 Darryl D. Holm , Vakhtang Putkaradze , Cesare Tronci

In this paper, we consider the full compressible, viscous, non-resistive MHD system under the assumption that the fluids move on a plane while the magnetic field is oriented vertically. Within the framework of Besov spaces, by introducing…

Analysis of PDEs · Mathematics 2024-08-15 Xiaoping Zhai , Shunhang Zhang

The present article introduces a generalization of the (multisymplectic) Hamiltonian field theory for a Lagrangian density, allowing the formulation of this kind of field theories for variational problem of more general nature than those…

Mathematical Physics · Physics 2025-09-15 Guadalupe Quijón , Santiago Capriotti

I review the problem of motion for small bodies in General Relativity, with an emphasis on developing a self-consistent treatment of the gravitational self-force. An analysis of the various derivations extant in the literature leads me to…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Adam Pound

We present dynamical description of gravitational collapse in view of Misner and Sharp's formalism. Matter under consideration is a complicated fluid consistent with plane symmetry which we assume to undergo dissipation in the form of heat…

General Relativity and Quantum Cosmology · Physics 2014-11-20 M. Sharif , Zakia Rehmat

Recently a notion of gravitational aether is advocated to solve the cosmological constant problem.Through the modification of the source of gravity one finds that the effective Newton's constant is source dependent so as to provide a simple…

General Relativity and Quantum Cosmology · Physics 2009-11-09 Xiao-Mei Kuang , Yi Ling

We study the variational principle over an Hilbert-Einstein like action for an extended geometry taking into account torsion and non-metricity. By extending the semi-Riemannian geometry, we obtain an effective energy-momentum tensor which…

General Relativity and Quantum Cosmology · Physics 2016-03-30 Jesús Martín Romero , Mauricio Bellini , José Edgar Madriz Aguilar

We consider the fully-coupled McKean-Vlasov equation with multi-time-scale potentials, and all the coefficients depend on the distributions of both the slow component and the fast motion. By studying the smoothness of the solution of the…

Probability · Mathematics 2022-04-28 Yun Li , Fuke Wu , Longjie Xie

In this article, we generalize the theory of discrete Lagrangian mechanics and variational integrators in two principal directions. First, we show that Lagrangian submanifolds of symplectic groupoids give rise to discrete dynamical systems,…

Symplectic Geometry · Mathematics 2015-11-04 Juan Carlos Marrero , David Martín de Diego , Ari Stern

We propose a geometrical approach to the investigation of Hamiltonian systems on (Pseudo) Riemannian manifolds. A new geometrical criterion of instability and chaos is proposed. This approach is more generic than well known reduction to the…

Astrophysics · Physics 2007-05-23 A. A. Kocharyan

A theory of gravitation is constructed in which all homogeneous and isotropic solutions are nonsingular, and in which all curvature invariants are bounded. All solutions for which curvature invariants approach their limiting values approach…

General Relativity and Quantum Cosmology · Physics 2009-10-22 R. Brandenberger , V. Mukhanov , A. Sornborger

We revisit the geodesic approach to ideal hydrodynamics and present a related geometric framework for Newton's equations on groups of diffeomorphisms and spaces of probability densities. The latter setting is sufficiently general to include…

Symplectic Geometry · Mathematics 2024-01-25 Boris Khesin , Gerard Misiolek , Klas Modin

Solutions of the classical and nonlocal Gross-Pitaevskii (GP) equation with a parabolic potential and a gain term are derived by using a second order nonisospectral Ablowitz-Kaup-Newell-Segur system and reduction technique of double…

Exactly Solvable and Integrable Systems · Physics 2020-12-30 Shi-min Liu , Hua Wu , Da-jun Zhang

In a geometric unified theory there is an energy momentum equation, apart from the field equations and equations of motion. The general relativity Einstein equation with cosmological constant follows from this energy momentum equation for…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Gustavo R. Gonzalez-Martin

The Problem of Time in Quantum Gravity is analyzed from a classical presymplectic perspective. In the first part of the paper the Three Space Approach to General Relativity is introduced via the Barbour-Foster-\'O Murchadha action and the…

General Relativity and Quantum Cosmology · Physics 2013-01-01 Vasudev Shyam , B. S. Ramachandra

We obtain the Maxwell-J\"uttner distribution function at first order in the post-Newtonian approximation within the framework of general relativity. Taking into account the aforesaid distribution function, we compute the particle four-flow…

General Relativity and Quantum Cosmology · Physics 2016-04-01 G. M. Kremer , Martín G. Richarte , Karla Weber

We introduce new invariants associated to collections of compact subsets of a symplectic manifold. They are defined through an elementary-looking variational problem involving Poisson brackets. The proof of the non-triviality of these…

Symplectic Geometry · Mathematics 2015-03-19 Lev Buhovsky , Michael Entov , Leonid Polterovich

This paper investigates the stability and large-time behavior of solutions to the rotating Boussinesq system under the influence of a general gravitational potential $\Psi$, which is widely used to model the dynamics of stratified…

Analysis of PDEs · Mathematics 2025-04-16 Song Jiang , Quan Wang

We prove the invariant of the symplectic capacity for the Zakharov system on a torus. If the Zakharov solution map is well-defined, then it can be regarded as a symplectomorphism. Thus, we first show the global well-posedness via the local…

Analysis of PDEs · Mathematics 2022-07-20 Sunghyun Hong
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