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Related papers: Modelling the Earth's magnetic field

200 papers

In this letter, we discuss generation of magnetic field from cosmological perturbations. We consider the evolution of three component plasma (electron, proton and photon) evaluating the collision term between elecrons and photons up to the…

Astrophysics · Physics 2009-11-10 Keitaro Takahashi , Kiyotomo Ichiki , Hiroshi Ohno , Hidekazu Hanayama

For magnetic field calculations, cylindrical permanent magnets are often approximated as ideal, azimuthally symmetric solenoids. Despite the frequent usage of this approximation, research papers demonstrating the validity and limitations of…

Instrumentation and Detectors · Physics 2022-07-21 David Shulman

A variety of observations impose upper limits at the nano Gauss level on magnetic fields that are coherent on inter-galactic scales while blazar observations indicate a lower bound $\sim 10^{-16}$ Gauss. Such magnetic fields can play an…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-15 Tanmay Vachaspati

Recent spectro-polarimetric observations have provided detailed measurements of magnetic field, velocity and intensity during events of magnetic field intensification in the solar photosphere. We consider the temporal evolution of the…

Solar and Stellar Astrophysics · Physics 2015-05-14 S. Danilovic , M. Schüssler , S. K. Solanki

The strength of the total magnetic field in our Milky Way from radio Zeeman and synchrotron measurements is about 6 muG near the Sun and several mG in dense clouds, pulsar wind nebulae, and filaments near the Galactic Center. Diffuse…

Astrophysics · Physics 2009-11-13 Rainer Beck

The generation of large-scale magnetic fields is studied in dilaton electromagnetism in inflationary cosmology, taking into account the dilaton's evolution throughout inflation and reheating until it is stabilized with possible entropy…

Astrophysics · Physics 2008-11-26 Kazuharu Bamba , J. Yokoyama

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

Magnetic field reconnection is often invoked to explain electromagnetic energy conversion in planetary magnetospheres, stellar coronae, and other astrophysical objects. Because of the huge dynamic range of magnetic fields in these bodies,…

Solar and Stellar Astrophysics · Physics 2015-05-19 Forrest S. Mozer , Arthur Hull

We calculate analytically the spin-orbital decomposition of the angular momentum using completely non-paraxial fields that have certain degree of linkage of electric and magnetic lines. The split of the angular momentum into spin-orbital…

Optics · Physics 2018-09-26 M Arrayás , J L Trueba

Three-dimensional global magnetohydrodynamic simulations of the solar wind - magnetosphere - ionosphere system are carried out to explore the dependence of the magnetospheric reconnection voltage, the ionospheric transpolar potential, and…

Solar and Stellar Astrophysics · Physics 2009-04-07 XIONG Ming , PENG Zhong , HU Youqiu , ZHENG Huinan

Magnetic fields play a fundamental role for interior and atmospheric properties of M dwarfs and greatly influence terrestrial planets orbiting in the habitable zones of these low-mass stars. Determination of the strength and topology of…

Solar and Stellar Astrophysics · Physics 2020-12-23 Oleg Kochukhov

Spectropolarimetric observations show that many low-mass stars possess large-scale poloidal magnetic fields with considerable dipole component, which in some cases exhibit temporal dynamics - cycles or reversals. Although it is widely…

Solar and Stellar Astrophysics · Physics 2025-07-02 Anna Guseva , Ludovic Petitdemange , Charly Pinçon

The measurement of Zeeman splitting in spectral lines---both in emission and absorption---can provide direct estimates of the magnetic field strength and direction in atomic and molecular clouds, both in our own Milky Way and in external…

The large-scale magnetic fields we observe today in galaxies and galaxy clusters could be the result of a pure quantum effect taking place during inflation, to wit, the creation of particles (photons) out from the vacuum in a curved…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-26 Leonardo Campanelli

We consider a scale-invariant helical magnetic field generated during inflation. We show that, if the mean magnetic helicity density of such a field is measured, it can be used to determine a lower bound on the duration of inflation. Upper…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-13 Tina Kahniashvili , Axel Brandenburg , Ruth Durrer , Alexander G. Tevzadze , Winston Yin

We introduce a technique to decompose the scattered near field of two-dimensional arbitrary metaatoms into its multipole contributions. To this end we expand the scattered field upon plane wave illumination into cylindrical harmonics as…

In this article, we derive a magnetic dipole model for two identical, electrically conducting, and permeable spheres that are exposed to an oscillating homogeneous magnetic field. Our model predicts both amplitude and phase of the induced…

Classical Physics · Physics 2022-12-07 Florian Bönsel , Alfred Müller , Rafael Psiuk

A properly calibrated longitudinal magnetograph is an instrument that measures circular polarization and gives an estimation of the magnetic flux density in each observed resolution element. This usually constitutes a lower bound of the…

Solar and Stellar Astrophysics · Physics 2015-05-27 A. Asensio Ramos , M. J. Martinez Gonzalez , R. Manso Sainz

The spontaneous relaxation rates for an atom in free space and close to an absorbing surface are calculated to various orders of the electromagnetic multipole expansion. The spontaneous decay rates for dipole, quadrupole and octupole…

Quantum Physics · Physics 2010-08-16 J. A. Crosse , Stefan Scheel

The effect of magnetic fields on the frequencies of toroidal oscillations of neutron stars is derived to lowest order. Interpreting the fine structure in the QPO power spectrum of magnetars following giant flares reported by Strohmayer and…

High Energy Astrophysical Phenomena · Physics 2009-08-17 R. Shaisultanov , D. Eichler