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Related papers: Do spherical alpha^2-dynamos oscillate?

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The constraint imposed by magnetic helicity conservation on the alpha effect is considered for both magnetically and flow dominated self-organizing plasmas. Direct numerical simulations are presented for a dominant contribution to the alpha…

High Energy Astrophysical Phenomena · Physics 2015-06-18 F. Ebrahimi , A. Bhattacharjee

A lattice system of spinor atoms or molecules experiencing quadratic Zeeman effect is considered. This can be an optical lattice with sufficiently deep wells at lattice sites, so that the system is in an isolating state, where atoms are…

Quantum Gases · Physics 2018-11-21 V. I. Yukalov , E. P. Yukalova

The asymmetric shape of reversals of the Earth's magnetic field indicates a possible connection with relaxation oscillations as they were early discussed by van der Pol. A simple mean-field dynamo model with a spherically symmetric $\alpha$…

Geophysics · Physics 2009-05-20 Frank Stefani , Mingtian Xu , Luca Sorriso-Valvo , Gunter Gerbeth , Uwe Günther

The Babcock-Leighton type of dynamo has received recent support in terms of the discovery in the observational records of systematic cycle-to-cycle variations in the tilt angle of sunspot groups. It has been proposed that these variations…

Solar and Stellar Astrophysics · Physics 2011-08-08 R. H. Cameron

A magnetic flux tube may be considered both as a separate body and as a confined field. As a field, it is affected both by the cyclonic convection ($\alpha$-effect) and differential rotation ($\Omega$-effect). As a body, the tube…

Astrophysics · Physics 2007-05-23 L. H. Li , S. Sofia

Dynamic buckling is addressed for complete elastic spherical shells subject to a rapidly applied step in external pressure. Insights from the perspective of nonlinear dynamics reveal essential mathematical features of the buckling…

Soft Condensed Matter · Physics 2019-02-07 Jan Sieber John W. Hutchinson , J. Michael T. Thompson

A convection-driven MHD dynamo in a rotating spherical shell, with clearly defined structural elements in the flow and magnetic field, is simulated numerically. Such dynamos can be called deterministic, in contrast to those explicitly…

Astrophysics · Physics 2008-11-26 A. V. Getling , R. D. Simitev , F. H. Busse

Nuclear rings at centers of barred galaxies exhibit strong star formation activities. They are thought to undergo gravitational instability when sufficiently massive. We approximate them as rigidly-rotating isothermal objects and…

Astrophysics of Galaxies · Physics 2016-09-28 Woong-Tae Kim , Sanghyuk Moon

The wave-particle alpha-channeling effect is generalized to include rotating plasma. Specifically, radio frequency waves can resonate with alpha particles in a mirror machine with ExB rotation to diffuse the alpha particles along…

Plasma Physics · Physics 2008-11-13 Abraham J. Fetterman , Nathaniel J. Fisch

It is shown that in the presence of anisotropic kinetic dissipation existence of scale invariant power law spectrum of plasma turbulence is possible. Obtained scale invariant spectrum is not associated with the constant flux of any physical…

Astrophysics · Physics 2009-11-13 Grigol Gogoberidze

This paper extends the Lorentz-Abraham model of an electron (i.e. the equations of motion for a small spherical shell of charge, which is rigid in its proper frame) to treat a small spherically symmetric charge distribution, allowing for…

Classical Physics · Physics 2016-04-27 P. D. Flammer

Relative drifts between different species or particle populations are characteristic to solar plasma outflows, e.g., in the fast streams of the solar winds, coronal mass ejections and interplanetary shocks. This paper characterizes the…

Space Physics · Physics 2020-07-01 M. A. Rehman , S. M. Shaaban , P. H. Yoon , M. Lazar , S. Poedts

We show that hemispherical dynamos can result from weak equatorial symmetry breaking of the flow in the interior of planets and stars. Using a model of spherical dynamo, we observe that the interaction between a dipolar and a quadrupolar…

Earth and Planetary Astrophysics · Physics 2015-05-13 Basile Gallet , François Pétrélis

The kinetic theory for the cylindrical plasma, produced by the cylindrically symmetric (azimuthal mode number m=0) helicon wave, is developed with accounting for the cylindrical geometry and the radial inhomogeneity of the helicon wave and…

Plasma Physics · Physics 2022-02-08 V. V. Mikhailenko , Hae June Lee , V. S. Mikhailenko

The study of dynamo action in astrophysical objects classically involves two timescales: the slow diffusive one and the fast advective one. We investigate the possibility of field amplification on an intermediate timescale associated with…

Classical Physics · Physics 2009-11-13 Emmanuel Dormy , David Gerard-Varet

We study the dynamics of a spherically symmetric thin shell of perfect fluid embedded in d-dimensional Anti-de Sitter space-time. In global coordinates, besides collapsing solutions, oscillating solutions are found where the shell bounces…

General Relativity and Quantum Cosmology · Physics 2015-07-07 Javier Mas , Alexandre Serantes

We solve the problem of a dimer moving on a spherical surface and find that its binding energy and wave function are sensitive to the total angular momentum. The dimer gets squeezed in the direction orthogonal to the center-of-mass motion…

Quantum Gases · Physics 2025-05-20 A. Tononi , D. S. Petrov , M. Lewenstein

We quantify possible differences between turbulent dynamo action in the Sun and the dynamo action studied in idealized simulations. For this purpose we compare Fourier-space shell-to-shell energy transfer rates of three incrementally more…

Solar and Stellar Astrophysics · Physics 2011-07-08 R. Moll , J. Pietarila Graham , J. Pratt , R. H. Cameron , W. -C. Müller , M. Schüssler

The collisionless dissipation of anisotropic Alfv\'enic turbulence is a promising candidate to solve the solar wind heating problem. Extensive studies examined the kinetic properties of Alfv\'en waves in simple Maxwellian or bi-Maxwellian…

Solar and Stellar Astrophysics · Physics 2015-05-12 Yuguang Tong , Stuart D. Bale , Christopher H. K. Chen , Chadi S. Salem , Daniel Verscharen

We revisit the possible turbulent sources of the solar dynamo. Studying axisymmetric mean-field dynamo models, we find that the large-scale poloidal magnetic field could be generated not only by the famous alpha effect, but also by the…

Astrophysics · Physics 2008-12-09 V. V. Pipin , N. Seehafer