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Related papers: Velocity Gradients as a Tracer for Magnetic Fields

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The k-filtering technique and wave polarization analysis are applied to Cluster magnetic field data to study plasma turbulence at the scale of the ion gyroradius in the fast solar wind. Waves are found propagating in directions nearly…

Solar and Stellar Astrophysics · Physics 2015-06-15 Owen W. Roberts , Xing Li , Bo Li

Altermagnets constitute a class of collinear magnets with momentum-dependent spin splitting and vanishing net magnetization. Direct observation of the characteristic altermagnetic spin splitting, however, remains challenging. Indirect…

Mesoscale and Nanoscale Physics · Physics 2026-02-18 Arsen Herasymchuk , Karl Bergson Hallberg , Erik Wegner Hodt , Jacob Linder , E. V. Gorbar , Pavlo Sukhachov

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

Motivated by recent observations of distinct parallel and perpendicular signatures in magnetic helicity measurements segregated by wave period and angle between the local magnetic field and the solar wind velocity, this paper undertakes a…

Plasma Physics · Physics 2015-06-19 Kristopher G. Klein , Gregory G. Howes , Jason M. TenBarge , John J. Podesta

We describe a novel pulsed magnetic gradiometer based on the optical interference of sidebands generated using two spatially separated alkali vapor cells. The sidebands are produced with high efficiency using parametric frequency conversion…

Atomic Physics · Physics 2021-11-25 Kaleb Campbell , Ying-Ju Wang , Igor Savukov , Peter Schwindt , Yuan-Yu Jau , Vishal Shah

Several variants of stochastic gradient descent (SGD) have been proposed to improve the learning effectiveness and efficiency when training deep neural networks, among which some recent influential attempts would like to adaptively control…

Machine Learning · Computer Science 2020-10-22 Jie Liu , Chen Lin , Chuming Li , Lu Sheng , Ming Sun , Junjie Yan , Wanli Ouyang

This work has the main objective to provide a detailed investigation of cosmic ray propagation in magnetohydrodynamic turbulent fields generated by forcing the fluid velocity field at large scales. It provides a derivation of the particle…

High Energy Astrophysical Phenomena · Physics 2016-03-25 Romain Cohet , Alexandre Marcowith

High-quality spatially-resolved measurements of electric fields are critical to understanding charge injection, charge transport, and charge trapping in semiconducting materials. Here, we report a variation of frequency-modulated Kelvin…

Mesoscale and Nanoscale Physics · Physics 2017-10-30 Ryan P. Dwyer , Louisa M. Smieska , Ali Moeed Tirmzi , John A. Marohn

We show that it is possible to measure Alfv\'enic Mach numbers, defined as the shock velocity in the flow divided by the Alfv\'en velocity, for low-velocity (V$_{shock}$ $\lesssim$ 100 km$\,$s$^{-1}$) radiative shocks. The method combines…

Instrumentation and Methods for Astrophysics · Physics 2015-09-23 P. Hartigan , A. Wright

We study gradient magnetometry with an ensemble of atoms with arbitrary spin. We calculate precision bounds for estimating the gradient of the magnetic field based on the quantum Fisher information. For quantum states that are invariant…

Quantum Physics · Physics 2018-06-08 Iagoba Apellaniz , Inigo Urizar-Lanz , Zoltan Zimboras , Philipp Hyllus , Geza Toth

Recent studies provide evidence for the multi-scale nature of magnetic turbulence in the plasma sheet. Wavelet methods represent modern time series analysis techniques suitable for the description of statistical characteristics of…

Space Physics · Physics 2016-09-08 W. Baumjohann , R. Nakamura , A. Runov , M. Volwerk , T. L. Zhang , A. Balogh

Magnetic properties of metals are investigated through electronic structure calculations based on the recently-proposed magnetic-field-containing relativistic tight-binding approximation (MFRTB) method [Phys. Rev. B \textbf{91}, 075122…

Strongly Correlated Electrons · Physics 2017-05-31 Masahiko Higuchi , Katsuhiko Higuchi

Turbulence in the solar wind is characterized by Alfv\'enic fluctuations that exhibit spherical polarization, a geometric condition resulting in the nearly constant magnitude of the magnetic field. This property persists even during the…

Plasma Physics · Physics 2026-05-07 Anna Tenerani , Marco Velli

In this work, a new non-stationary multiple point geostatistical algorithm called vector field-based simulation is proposed. The motivation behind this work is the modeling of a certain structures that exhibit directional features with…

Image and Video Processing · Electrical Eng. & Systems 2018-12-31 Viviana Lorena Vargas , Sinesio Pesco

We describe and characterize a method for estimating the pressure field corresponding to velocity field measurements, such as those obtained by using particle image velocimetry. The pressure gradient is estimated from a time series of…

Fluid Dynamics · Physics 2014-01-22 John O. Dabiri , Sanjeeb Bose , Brad J. Gemmell , Sean P. Colin , John H. Costello

We investigate numerically the long-time behavior of balanced Alfven wave turbulence forced at intermediate scales. Whereas the usual constant-flux solution is found at the smallest scales, two new scalings are obtained at the forcing…

Astrophysics · Physics 2007-10-25 S. Galtier , S. Nazarenko

Galactic winds probe how stellar feedback regulates the mass and metallicity of galaxies. Observations show that galactic winds are multiphase and magnetised. In the local Universe, the dense phase is traced by emission and absorption…

In this paper, we aim to estimate the vertical gradients in the rotational velocity of the Galaxy. This is carried out in the framework of a global thin disc model approximation. The predicted gradient values coincide with the observed…

Astrophysics of Galaxies · Physics 2015-03-13 Joanna Jałocha , Łukasz Bratek , Marek Kutschera , Piotr Skindzier

Adjoint methods can speed up stellarator optimisation by providing gradient information more efficiently compared to finite-difference evaluations. Adjoint methods are herein applied to vacuum magnetic fields, with objective functions…

Plasma Physics · Physics 2022-02-16 Richard Nies , Elizabeth J. Paul , Stuart R. Hudson , Amitava Bhattacharjee

Using direct numerical simulations of three-dimensional magnetohydrodynamic (MHD) turbulence the spatio-temporal behavior of magnetic field fluctuations is analyzed. Cases with relatively small, medium and large values of a mean background…

Plasma Physics · Physics 2016-12-21 R. Lugones , P. Dmitruk , P. D. Mininni , M. Wan , W. H. Matthaeus
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