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Related papers: From reversing to hemispherical dynamos

200 papers

When a differentially rotating magnetic star undergoes ``turn-over'', i.e., its magnetic symmetry axis is inclining at a gradually increasing angle with respect to its invariant angular momentum axis up to the perpendicular position…

Astrophysics · Physics 2007-05-23 V. S. Geroyannis , P. J. Papasotiriou , I. Valiaka

Rotational energy dissipation in the solar system confines the planets to the ecliptic, this can be thought of as a dimensional reduction from three dimensions to two. It is argued that the same mechanism restricts five dimensional matter…

General Relativity and Quantum Cosmology · Physics 2019-01-01 Mark D. Roberts

The solar cycle and its associated magnetic activity are the main drivers behind changes in the interplanetary environment and Earth's upper atmosphere (commonly referred to as space weather and climate). In recent years there has been an…

Solar and Stellar Astrophysics · Physics 2013-10-08 Andrés Muñoz-Jaramillo , Laura A. Balmaceda , Edward E. DeLuca

We present axisymmetric numerical simulations of the solar interior, including the convection zone and an extended radiative interior. We find that differential rotation in the convection zone induces a toroidal field from an initially…

Solar and Stellar Astrophysics · Physics 2015-05-30 T. M. Rogers

We consider a composite spin-half particle moving in spatially-varying scalar and vector fields. The vector field is assumed to couple to a conserved charge, but no assumption is made about either the structure of the composite or its…

Nuclear Theory · Physics 2008-11-26 D. R. Phillips , M. C. Birse , S. J. Wallace

The availability of large magnetic fields at international facilities and of simulated magnetic fields that can reach the flux-quantum-per-unit-area level in cold atoms, calls for systematic studies of orbital effects of the magnetic field…

Strongly Correlated Electrons · Physics 2018-08-20 S. Acheche , L-F. Arsenault , A. -M. S. Tremblay

A thermodynamic model for the generation of magnetic fields in the planets is proposed, considering crossed effects between gravitational and electric forces. The magnetic field of the Earth is estimated and found to be in agreement with…

Astrophysics · Physics 2007-05-23 F. X. Alvarez

Fast changes of Earth's magnetic field could be explained by inviscid and diffusion-less quasi-geostrophic (QG) Magneto-Coriolis modes. We present a hybrid QG model with columnar flows and three-dimensional magnetic fields and find modes…

Geophysics · Physics 2021-02-24 Felix Gerick , Dominique Jault , Jerome Noir

Magnetic fields correlated on kiloparsec scales are seen in spiral galaxies. Their origin could be due to amplification of a small seed field by a turbulent galactic dynamo. We review the current status of the galactic dynamo, especially…

Astrophysics · Physics 2007-05-23 Kandaswamy Subramanian

For a simple spherically symmetric mean-field dynamo model we investigate the possibility of determining the radial dependence of the coefficient $\alpha$. Growth rates for different magnetic field modes are assumed to be known by…

Astrophysics · Physics 2009-05-20 Frank Stefani , Gunter Gerbeth

Today, the generation of magnetic fields in solar-type stars and its relation to activity and rotation can coherently be explained, although it is certainly not understood in its entirety. Rotation facilitates the generation of magnetic…

Astrophysics · Physics 2009-11-13 A. Reiners , A. Scholz , J. Eislöffel , G. Hallinan , E. Berger , M. Browning , J. Irwin , M. Küker , S. Matt

We analyze the phases of an S=1/2 spin model on a lattice of coupled tetrahedra. The presence of both Heisenberg and antisymmetric, Dzyaloshinsky-Moriya interactions can lead to two types of symmetry-broken states: non-magnetic dimer order…

Strongly Correlated Electrons · Physics 2016-08-31 Valeri N. Kotov , Michael E. Zhitomirsky , Maged Elhajal , Frederic Mila

Convectively driven dynamos with rotation generating magnetic fields on scales large compared with the scale of the turbulent eddies are being reviewed. It is argued that such fields can be understood as the result of an alpha effect.…

Solar and Stellar Astrophysics · Physics 2011-08-19 A. Brandenburg , P. J. Käpylä , M. J. Korpi

Opher et al. 2006 showed that an interstellar magnetic field parallel to the plane defined by the deflection of interstellar hydrogen atoms can produce a north/south asymmetry in the distortion of the solar wind termination shock. This…

Astrophysics · Physics 2009-11-11 Merav Opher , Edward C. Stone , Paulett C. Liewer , Tamas Gombosi

The periodically varying Lorentz force of the periodic solar magnetic field generated by the solar dynamo can induce two kinds of motions: torsional oscillations and periodic variations in the meridional circulation. Observational evidence…

Solar and Stellar Astrophysics · Physics 2015-06-05 Arnab Rai Choudhuri

For collectively interacting repulsive particles driven on triangular substrates, we show that for certain directions of drive a spontaneous symmetry breaking phenomena occurs where the particles can flow in one of two directions that are…

Soft Condensed Matter · Physics 2009-11-10 C. Reichhardt , C. J. Olson Reichhardt

Convection and magnetic field generation in the Earth and planetary interiors are driven by both thermal and compositional gradients. In this work numerical simulations of finite-amplitude double-diffusive convection and dynamo action in…

Fluid Dynamics · Physics 2021-01-27 James F. Mather , Radostin D. Simitev

The spin splitting caused by the terms linear in wavevector in the effective Hamiltonian containing can give rise to the new magneto-oscillation phenomena in two-dimensional systems. It is shown that the joint action of the spin-dependent…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 S. A. Tarasenko , N. S. Averkiev

Extremely strong magnetic fields change the vacuum index of refraction. Although this polarization dependent effect is small for typical neutron stars, it is large enough to decouple the polarization states of photons traveling within the…

Astrophysics · Physics 2009-10-31 Jeremy S. Heyl , Nir J. Shaviv

Following some of the recent articles on hole super-conductivity and related phenomena by Hirsch \cite{H1,H2,H3}, a simple model is proposed to explain the observed low surface magnetic field of the expected quark stars. It is argued that…

Astrophysics · Physics 2015-05-13 Nandini Nag , Sutapa Ghosh , Roni Saha , Somenath Chakrabarty
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