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Related papers: Modes of a stellar system I: ergodic systems

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The mechanism for the relaxation of the cosmological constant is studied and elaborated. In the model used for the analysis of the relaxation mechanism the universe contains two components: a cosmological constant of an arbitrary size and…

General Relativity and Quantum Cosmology · Physics 2008-12-22 Hrvoje Stefancic

To comprehensively understand saturation of two-dimensional ($2$D) magnetized Kelvin-Helmholtz-instability-driven turbulence, energy transfer analysis is extended from the traditional interaction between scales to include eigenmode…

Plasma Physics · Physics 2023-07-26 B. Tripathi , A. E. Fraser , P. W. Terry , E. G. Zweibel , M. J. Pueschel , E. H. Anders

This paper contains a very simple and general proof that eigenfunctions of quantizations of classically ergodic systems become uniformly distributed in phase space. This ergodicity property of eigenfunctions f is shown to follow from a…

Mathematical Physics · Physics 2015-06-26 Steve Zelditch

I review several issues related to statistical description of gravitating systems in both static and expanding backgrounds. After briefly reviewing the results for the static background, I concentrate on gravitational clustering of…

Astrophysics · Physics 2009-02-16 T. Padmanabhan

A comparison between linear stability analysis and observations of pulsation modes in five delta Scuti stars, belonging to the same cluster, is presented. The study is based on the work by Michel et al. (1999), in which such a comparison…

Astrophysics · Physics 2009-06-23 J. C. Suarez , E. Michel , G. Houdek , F. Perez Hernandez , Y. Lebreton

A numerical simulation of vibrational excitation of molecules was devised, and used to excite computational models of common molecules into a prescribed, pure, normal vibration mode in the ground electronic state, with varying, controlable…

Astrophysics · Physics 2009-11-11 Renaud Papoular

The classic problem of the dynamic evolution of Langmuir electron waves in a collisionless plasma and their Landau damping is cast as a second-order, self-adjoint problem with a continuum spectrum of real and positive squared frequencies.…

Plasma Physics · Physics 2018-04-04 Jesus J. Ramos , Ryan L. White

We exploit a new theory of gravity proposed by Finzi, which gives stronger interaction at large scales, to study the thermodynamic description of galaxy clusters. We employ a statistical model to deduce various thermodynamics equations of…

General Relativity and Quantum Cosmology · Physics 2023-05-26 Abdul W. Khanday , Sudhaker Upadhyay , Naseer Iqbal , Prince A. Ganai

Context: Recent calculations of pulsation modes in rapidly rotating polytropic models and models based on the Self-Consistent Field method (MacGregor et al. 2007) have shown that the frequency spectrum of low degree pulsation modes can be…

Solar and Stellar Astrophysics · Physics 2015-05-13 D. R. Reese , M. J. Thompson , K. B. MacGregor , S. Jackson , A. Skumanich , T. S. Metcalfe

After their initial formation, disk galaxies are observed to be rotationally stable over periods of >6 Gyr, implying that any large velocity disturbances of stars and gas clouds are damped rapidly on the timescale of their rotation.…

Astrophysics of Galaxies · Physics 2022-11-08 John Herbert Marr

The Self-Organized Hydrodynamics model of collective behavior is studied on an annular domain. A modal analysis of the linearized model around a perfectly polarized steady-state is conducted. It shows that the model has only pure imaginary…

Mathematical Physics · Physics 2014-07-01 Pierre Degond , Hui Yu

We analyze a class of linear shell models subject to stochastic forcing in finitely many degrees of freedom. The unforced systems considered formally conserve energy. Despite being formally conservative, we show that these dynamical systems…

Mathematical Physics · Physics 2009-11-11 Jonathan C. Mattingly , Toufic Suidan , Eric Vanden-Eijnden

Recently, in [1], we presented the first combined non-parametric reconstruction of the three time-dependent functions that capture departures from the standard cosmological model, $\Lambda$CDM, in the expansion history and gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-08 Marco Raveri , Levon Pogosian , Matteo Martinelli , Kazuya Koyama , Alessandra Silvestri , Gong-Bo Zhao

We study the long-term dynamics of a planetary system composed of a star and a planet. Both bodies are considered as extended, non-spherical, rotating objects. There are no assumptions made on the relative angles between the orbital angular…

Earth and Planetary Astrophysics · Physics 2015-06-04 Cezary Migaszewski

Galactic dynamo models have generally relied on input parameters that are very challenging to constrain. We address this problem by developing a model that uses observable quantities as input: the galaxy rotation curve, the surface…

Astrophysics of Galaxies · Physics 2024-04-04 Luke Chamandy , Rion Glenn Nazareth , Gayathri Santhosh

An update is given on the current status of solar and stellar dynamos. At present, it is still unclear why stellar cycle frequencies increase with rotation frequency in such a way that their ratio increases with stellar activity. The…

Solar and Stellar Astrophysics · Physics 2015-06-15 Axel Brandenburg

We present results for the equilibrium statistics and dynamic evolution of moderately large ($n = {\mathcal{O}}(10^2 - 10^3)$) numbers of interacting point vortices on the unit sphere under the constraint of zero mean angular momentum. We…

Fluid Dynamics · Physics 2015-04-28 David G. Dritschel , Marcello Lucia , Andrew C. Poje

This work reports an extensive study of three-dimensional topological ordered phases that, in one of the directions behave like usual topological order concerning mobility of excitations, but in the perpendicular plane manifest type-II…

Strongly Correlated Electrons · Physics 2024-12-12 Heitor Casasola , Guilherme Delfino , Yizhi You , Paula F. Bienzobaz , Pedro R. S. Gomes

The thermal history of the Universe is included in the Debye Gravitational Theory (DGT) to describe the speed of rotation of the galaxies. The DGT incorporate the temperature of Debye in the entropic gravitational theory. According to the…

Astrophysics of Galaxies · Physics 2017-06-12 Carlos E. Navia

R-modes of a rotating neutron star are unstable because of the emission of gravitational radiation. We explore the saturation amplitudes of these modes determined by nonlinear mode-mode coupling. Modelling the star as incompressible allows…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Jeandrew Brink , Saul A. Teukolsky , Ira Wasserman