English
Related papers

Related papers: $f$-mode strengthening from a localized bipolar su…

200 papers

About 10 per cent of intermediate- and high-mass dwarf stars are observed to host a strong large-scale magnetic field at their surface, which is thought to be of fossil field origin. However, there are few inferences as to the magnetic…

Solar and Stellar Astrophysics · Physics 2022-02-23 Daniel Lecoanet , Dominic M. Bowman , Timothy Van Reeth

One of the intriguing characteristics of honeycomb lattices is the appearance of a pseudo-magnetic field as a result of mechanical deformation. In the case of graphene, the Landau quantization resulting from this pseudo-magnetic field has…

Motivated by the problem of the formation of active regions from a deep-seated solar magnetic field, we consider the nonlinear three-dimensional evolution of magnetic buoyancy instabilities resulting from a smoothly stratified horizontal…

Astrophysics · Physics 2009-11-13 Evy Kersale , David W. Hughes , Steven M. Tobias

Optical and infrared polarization mapping and recent Planck observations of the filamentary cloud L1495 in Taurus show that the large-scale magnetic field is approximately perpendicular to the long axis of the cloud. We use the HAWC+…

Many stars evolve into magnetic white dwarfs, and observations may help to understand when the magnetic field appears at the stellar surface, if and how it evolves during the cooling phase, and what are the mechanisms that generate it.…

Solar and Stellar Astrophysics · Physics 2021-10-04 S. Bagnulo , J. D. Landstreet

Several new features arise in the ground-state phase diagram of a spin-1 condensate trapped in an optical trap when the magnetic dipole interaction between the atoms is taken into account along with confinement and spin precession. The…

Quantum Gases · Physics 2010-02-06 Jonas A. Kjäll , Andrew M. Essin , Joel E. Moore

Ferromagnetism is typically discussed in terms of the exchange interaction and magnetic anisotropies. Yet real samples are inevitably affected by the magnetostatic dipole-dipole interaction. Because of this interaction, a theorem (R.B.…

Statistical Mechanics · Physics 2025-01-27 D. Pescia , A. Vindigni

We have analyzed the full set of SOHO/MDI f- and p-mode oscillation frequencies from 1996 to date in a search for evidence of solar radius evolution during the rising phase of the current activity cycle. Like Antia et al. (2000), we find…

Astrophysics · Physics 2009-11-06 W. A. Dziembowski , P. R. Goode , J. Schou

The helicity of a magnetic field is a fundamental property that is conserved in ideal MHD. It can be explored in the stellar context by mapping large-scale magnetic fields across stellar surfaces using Zeeman-Doppler imaging. A recent study…

Solar and Stellar Astrophysics · Physics 2021-03-12 K. Lund , M. Jardine , A. J. B. Russell , J. -F. Donati , R. Fares , C. P. Folsom

We perform direct numerical simulations of the equations of magnetohydrodynamics with external random forcing and in the presence of gravity. The domain is divided into two parts: a lower layer where the forcing is helical and an upper…

Solar and Stellar Astrophysics · Physics 2014-10-20 Dhrubaditya Mitra , A. Brandenburg , N. Kleeorin , I. Rogachevskii

The resistivity of disordered metallic layer sandwiched by two ferromagnetic layers at low-temperature is investigated theoretically. It is shown that the magnetic field acting at the interface does not affect the classical Boltzmann…

Mesoscale and Nanoscale Physics · Physics 2015-06-25 Gen Tatara , Hidetoshi Fukuyama

Over the past number of years, great strides have been made in identifying the various low-order magnetohydrodynamic wave modes observable in a number of magnetic structures found within the solar atmosphere. However, one aspect of these…

We investigate the nature of the dynamo bifurcation in a configuration applicable to the Earth's liquid outer core. Numerical studies on the stability domain of dipolar magnetic fields found a dichotomy between non-reversing…

Geophysics · Physics 2018-03-14 Ludovic Petitdemange

Current models of magnetars require extremely strong magnetic fields to explain their observed quiescent and bursting emission, implying that the field strength within the star's outer crust is orders of magnitude larger than the dipole…

Solar and Stellar Astrophysics · Physics 2016-04-07 Konstantinos N. Gourgouliatos , Toby Wood , Rainer Hollerbach

A hypothesis for sunspot formation is the buoyant emergence of magnetic flux tubes created by the strong radial shear at the tachocline. In this scenario, the magnetic field has to exceed a threshold value before it becomes buoyant and…

Solar and Stellar Astrophysics · Physics 2011-10-25 G. Guerrero , P. Käpylä

The aim of this study is to simulate the slow mode structures in the Hermean magnetosphere. We use a single fluid MHD model and a multipolar expansion of the Northward displaced Hermean magnetic field, to perform simulations with different…

Earth and Planetary Astrophysics · Physics 2016-08-17 J. Varela , F. Pantellini , M. Moncuquet

Previous work has introduced scale-split energy density \psi for a given vector field B in order to quantify the field stochasticity S(t). Application to turbulent magnetic fields leads to the prediction that tangling magnetic field by…

High Energy Astrophysical Phenomena · Physics 2020-02-26 Amir Jafari , Ethan Vishniac , Vignesh Vaikundaraman

In addition to sunspots, which represent the most easily visualized manifestation of solar magnetism, cutting-edge observations of the solar atmosphere have uncovered a plethora of magnetic flux tubes, down to the resolving power of modern…

Solar and Stellar Astrophysics · Physics 2025-02-27 M. Stangalini , G. Verth , V. Fedun , D. Perrone , M. Berretti , P. Bushby , S. Jafarzadeh , D. B. Jess , F. Giannattasio , P. H. Keys , R. Bruno , F. Berrilli

In this proceeding, we study the evolution of energy density fluctuations in the presence of a static and uniform magnetic field. By numerically solving the relativistic Boltzmann-Vlasov equation within the relaxation time approximation and…

Nuclear Theory · Physics 2025-11-06 Shreyansh S. Dave , Subrata Pal

We predict a mechanism of spontaneous stabilization of a uniaxial density wave in a two-dimensional metal with an isotropic Fermi surface in the presence of external magnetic field. The topological transformation of a closed Fermi surface…

Mesoscale and Nanoscale Physics · Physics 2019-09-05 Anatoly M Kadigrobov , Danko Radić , Aleksa Bjeliš