English
Related papers

Related papers: Current helicity and magnetic field anisotropy in …

200 papers

The magnetic phase diagram and low-energy magnon excitations of structurally and magnetically chiral MnSb2O6 are reported. The specific heat and the static magnetization are investigated in magnetic fields up to 9 and 30 T, respectively,…

Strongly Correlated Electrons · Physics 2016-09-21 J. Werner , C. Koo , R. Klingeler , A. N. Vasiliev , Y. A. Ovchenkov , A. S. Polovkova , G. V. Raganyan , E. A. Zvereva

Estimating the temperature of the solar wind particles and their anisotropies is particularly important for understanding the origin of these deviations from thermal equilibrium as well as their effects. In the absence of energetic events…

Space Physics · Physics 2016-08-17 V. Pierrard , M. Lazar , S. Poedts , S. Stverak , M. Maksimovic , P. M. Travnicek

We study a simple model for the solar dynamo in the framework of the Parker migratory dynamo, with a nonlinear dynamo saturation mechanism based on magnetic helicity conservation arguments. We find a parameter range in which the model…

Astrophysics · Physics 2009-11-07 N. Kleeorin , K. Kuzanyan , D. Moss , I. Rogachevskii , D. Sokoloff , H. Zhang

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

Magnetic helicity effects are discussed in laboratory and astrophysical settings. First, dynamo action in Taylor-Green flows is discussed for different boundary conditions. However, because of the lack of scale separation with respect to…

Astrophysics · Physics 2009-06-23 A Brandenburg , P J Käpylä

Magnetic helicity, $H$, measures magnetic linkages in a volume. The early theoretical development of helicity focused on magnetically closed systems in $\mathcal{V}$ bounded by $\mathcal{S}$. For magnetically closed systems,…

Solar and Stellar Astrophysics · Physics 2023-09-15 Peter W. Schuck , Mark G. Linton

The magnetic variance anisotropy ($\mathcal{A}_m$) of the solar wind has been used widely as a method to identify the nature of solar wind turbulent fluctuations; however, a thorough discussion of the meaning and interpretation of the…

Space Physics · Physics 2015-06-05 J. M. TenBarge , J. J. Podesta , K. G. Klein , G. G. Howes

In helical hydromagnetic turbulence with an imposed magnetic field (which is constant in space and time) the magnetic helicity of the field within a periodic domain is no longer an invariant of the ideal equations. Alternatively, there is a…

Astrophysics · Physics 2009-11-07 Axel Brandenburg , William H. Matthaeus

Using full three-dimensional magnetohydrodynamic numerical simulations, we study the effects of magnetic field sigmoidity or helicity on the properties of the fundamental kink oscillation of solar coronal loops. Our model consists of a…

Solar and Stellar Astrophysics · Physics 2020-05-20 N. Magyar , V. M. Nakariakov

Statistical analyses have shown that the sunward component of the interplanetary magnetic field, $\mathit{B}_{x}$ (Geocentric Solar Magnetospheric), moderately but significantly affects the auroral intensity. These observations have been…

Space Physics · Physics 2018-08-07 K. M. Laundal , J. P. Reistad , C. C. Finlay , N. Østgaard , P. Tenfjord , K. Snekvik , A. Ohma

We aim to understand the interplay between non-radial oscillations and stellar magnetic activity and test the feasibility of doing asteroseismology of magnetically active stars. We analyze 30 years of photometric time-series data, 3 years…

Solar and Stellar Astrophysics · Physics 2015-05-18 T. H. Dall , H. Bruntt , D. Stello , K. G. Strassmeier

We present the photospheric energy density of magnetic fields in two solar active regions inferred from observational vector magnetograms, and compare it with the possible different defined energy parameters of magnetic fields in the…

Solar and Stellar Astrophysics · Physics 2016-12-12 Hongqi Zhang

We have studied by Monte Carlo simulations the thermal behaviour of a small (N=13 particles) cluster described by a Heisenberg model, including nearest-neighbour ferromagnetic interactions and radial surface anisotropy, in an applied…

Statistical Mechanics · Physics 2016-08-16 Laura Hernández , Claire Pinettes

The power spectrum of the evolving solar wind shows evidence of a spectral break between an inertial range of turbulent fluctuations at higher frequencies and a "$1/f$" like region at lower frequencies. In the ecliptic plane at $\sim 1$ AU,…

Solar and Stellar Astrophysics · Physics 2009-09-24 R. M. Nicol , S. C. Chapman , R. O. Dendy

Photon helicity-dependent photocurrent is measured at zero magnetic field on a device based on an ensemble of InGaAs/GaAs quantum dots that are embedded into a GaAs-based p-i-n diode. Our main goal is to take advantage of the long electron…

Solar active regions and sunspots are believed to be formed by the emergence of strong toroidal magnetic flux from the solar interior. Modeling of such events has focused on the dynamics of compact magnetic entities, colloquially known as…

Solar and Stellar Astrophysics · Physics 2021-03-17 Bhishek Manek , Nicholas Brummell

The dual symmetry between the electric and magnetic fields underlies Maxwell's electrodynamics. Due to this symmetry one can describe topological properties of an electromagnetic field in free space and obtain the conservation law of…

Optics · Physics 2015-12-31 E. O. Kamenetskii , M. Berezin , R. Shavit

Solar eruptive events such as flares and coronal mass ejection (CME)-driven shocks can release solar energetic particles (SEPs) into the heliosphere. The heliospheric current sheet (HCS) is a large-scale structure that separates regions of…

Solar and Stellar Astrophysics · Physics 2026-04-22 C. Han , R. F. Wimmer-Schweingruber , P. Kühl , L. Berger , Z. Ding , A. Kollhoff , Q. Shi , Z. Xu , M. Qin , M. Wang

The decay of a turbulent magnetic field is slower with helicity than without. Furthermore, the magnetic correlation length grows faster for a helical than a nonhelical field. Both helical and nonhelical decay laws involve conserved…

Plasma Physics · Physics 2025-01-08 Axel Brandenburg , Aikya Banerjee

Context: The presence of a turbulent magnetic field in the quiet Sun has been unveiled observationally using different techniques. The magnetic field is quasi-isotropic and has field strengths weaker than 100G. It is pervasive and may host…

Solar and Stellar Astrophysics · Physics 2016-11-26 A. López Ariste , A. Sainz Dalda