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The nonlinear force-free field (NLFFF) model is often used to describe the solar coronal magnetic field, however a series of earlier studies revealed difficulties in the numerical solution of the model in application to photospheric…

The ideal imaging system would efficiently capture information about all fundamental properties light: intensity, direction, wavelength, and polarization. Most common imaging systems only map the spatial degrees of freedom of light onto a…

Optics · Physics 2023-01-26 Conner Ballew , Gregory Roberts , Andrei Faraon

Routine measurements of the solar magnetic field are mainly carried out in the photosphere. Therefore, one has to infer the field strength in the higher layers of the solar atmosphere from the measured photospheric field based on the…

Solar and Stellar Astrophysics · Physics 2015-05-20 Tilaye Tadesse , T. Wiegelmann , B. Inhester , A. Pevtsov

In this paper we consider the lens rigidity problem with partial data for conformal metrics in the presence of a magnetic field on a compact manifold of dimension $\geq 3$ with boundary. We show that one can uniquely determine the conformal…

Differential Geometry · Mathematics 2016-05-23 Hanming Zhou

We develop a two-scale formalism to determine global magnetic helicity spectra in systems where the local magnetic helicity has opposite signs on both sides of the equator, giving rise to cancelation with conventional methods. We verify…

Solar and Stellar Astrophysics · Physics 2017-02-07 Axel Brandenburg , Gordon J. D. Petrie , Nishant K. Singh

Measuring magnetic fields in the interstellar medium and obtaining their distribution along line-of-sight is very challenging with the traditional techniques. The Velocity Gradient Technique (VGT), which utilizes anisotropy of…

Astrophysics of Galaxies · Physics 2022-04-27 Yue Hu , A. Lazarian , Q. Daniel Wang

Inferring the three-dimensional (3D) solar atmospheric structures from observations is a critical task for advancing our understanding of the magnetic fields and electric currents that drive solar activity. In this work, we introduce a…

Standard statistical analysis of the magnetic properties of the quiet Sun rely on simple histograms of quantities inferred from maximum-likelihood estimations. Because of the inherent degeneracies, either intrinsic or induced by the noise,…

Solar and Stellar Astrophysics · Physics 2014-12-03 A. Asensio Ramos , M. J. Martínez González

We propose a novel paradigm to vector magnetometry based on machine learning. Unlike conventional schemes where one measured signal explicitly connects to one parameter, here we encode the three-dimensional magnetic-field information in the…

Instrumentation and Detectors · Physics 2023-10-04 Xin Meng , Youwei Zhang , Xichang Zhang , Shenchao Jin , Tingran Wang , Liang Jiang , Liantuan Xiao , Suotang Jia , Yanhong Xiao

We propose a magnetometer for the precise measurement of AC magnetic fields that uses a Terbium-doped optical fiber with half-waveplates built into it at specified distances. Our scheme uses an open-loop quantum control technique called…

Quantum Physics · Physics 2018-07-25 Manish K. Gupta , Jonathan Kunjummen , Xiaoting Wang , Jonathan P. Dowling

A putative temporally varying circulation-free magnetic-field configuration is inferred in an equatorial segment of the solar convection zone from the helioseismologically inferred angular-velocity variation, assuming that the predominant…

Solar and Stellar Astrophysics · Physics 2015-06-11 H. M. Antia , S. M. Chitre , D. O. Gough

The aim of this paper is to present an extragradient method for variational inequality associated to a point-to-set vector field in Hadamard manifolds and to study its convergence properties. In order to present our method the concept of…

Optimization and Control · Mathematics 2018-04-26 E. E. A. Batista , G. C. Bento , O. P. Ferreira

Vector tomography methods intend to reconstruct and visualize vector fields in restricted domains by measuring line integrals of projections of these vector fields. Here, we deal with the reconstruction of irrotational vector functions from…

Quantitative Methods · Quantitative Biology 2017-05-03 Alexandra Koulouri

Advances in vectorial polarisation-resolved imaging are bringing new capabilities to applications ranging from fundamental physics through to clinical diagnosis. Imaging polarimetry requires determination of the Mueller matrix (MM) at every…

Obtaining observational constraints on the role of turbulent effects for the solar dynamo is a difficult, yet crucial, task. Without such knowledge, the full picture of the operation mechanism of the solar dynamo cannot be formed. The…

Solar and Stellar Astrophysics · Physics 2021-10-04 A. P. Prabhu , N. K. Singh , M. J. Käpylä , A. Lagg

We consider the problem of determination of a magnetic field from three dimensional polarimetric neutron tomography data. We see that this is an example of a non-Abelian ray transform and that the problem has a globally unique solution for…

Analysis of PDEs · Mathematics 2019-10-21 Naeem M. Desai , William R. B. Lionheart , Morten Sales , Markus Strobl , Søren Schmidt

The solar magnetic field is key to understanding the physical processes in the solar atmosphere. Nonlinear force-free codes have been shown to be useful in extrapolating the coronal field upward from underlying vector boundary data.…

Astrophysics · Physics 2008-02-29 T. Wiegelmann , J. K. Thalmann , C. J. Schrijver , M. L. Derosa , T. R. Metcalf

In this paper, we came to conclusion that there is a significant systematic error in the SDO/HMI vector magnetic data, which reveals itself in a significant deviation of the lines of the knot magnetic fields from the radial direction. The…

Solar and Stellar Astrophysics · Physics 2017-11-23 G. V. Rudenko , I. S. Dmitrienko

The wave equation for vectors and symmetric tensors in spherical coordinates is studied under the divergence-free constraint. We describe a numerical method, based on the spectral decomposition of vector/tensor components onto spherical…

General Relativity and Quantum Cosmology · Physics 2009-11-23 Jerome Novak , Jean-Louis Cornou , Nicolas Vasset

We demonstrate an all-optical magnetometer capable of measuring the magnitude and direction of a magnetic field using nonlinear magneto-optical rotation in a cesium vapor. Vector capability is added by effective modulation of the field…

Atomic Physics · Physics 2015-06-19 B. Patton , E. Zhivun , D. C. Hovde , D. Budker