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Knowledge of the structure of the coronal magnetic field is important for our understanding of many solar activity phenomena, e.g. flares and CMEs. However, the direct measurement of coronal magnetic fields is not possible with present…

Astrophysics · Physics 2020-01-29 T. Wiegelmann , T. Neukirch

A spectral method is described for solving coupled elliptic problems on an interior and an exterior domain. The method is formulated and tested on the two-dimensional interior Poisson and exterior Laplace problems, whose solutions and their…

Numerical Analysis · Mathematics 2007-11-22 Piotr Boronski

Surface parameterization plays a fundamental role in many science and engineering problems. In particular, as genus-0 closed surfaces are topologically equivalent to a sphere, many spherical parameterization methods have been developed over…

Computational Geometry · Computer Science 2024-03-27 Gary P. T. Choi

The magnetic network extending from the photosphere (solar radius $\simeq R_\odot$) to lower corona ($R_\odot + 10$ Mm) plays an important role in the heating mechanisms of the solar atmosphere. Here we further develop the models with…

Solar and Stellar Astrophysics · Physics 2019-08-02 Frederick A. Gent , Ben Snow , Viktor Fedun , Robertus Erdelyi

We present methods for analyzing and designing cylindrical electromagnetic metasurfaces with non-circular cross sections based on conformal transformations. It can be difficult to treat surfaces with non-canonical geometries since they…

Optics · Physics 2022-03-10 Gengyu Xu , George V. Eleftheriades , Sean V. Hum

It is demonstrated that pseudocontact shift (PCS), viewed as a scalar or a tensor field in three dimensions, obeys an elliptic partial differential equation with a source term that depends on the Hessian of the unpaired electron probability…

Chemical Physics · Physics 2014-09-05 G. T. P. Charnock , Ilya Kuprov

Solar eruptive phenomena, like flares and coronal mass ejections(CMEs) are governed by magnetic fields. To describe the structure of these phenomena one needs information on the magnetic flux density and the electric current density vector…

Solar and Stellar Astrophysics · Physics 2015-06-17 Tilaye Tadesse , T. Wiegelmann , Pevtsov A Alexei , P. Macneice , S. Gosain

The time dependent Schrodinger equation inclusive of curvature effects is developed for a spinless electron constrained to motion on a toroidal surface and subjected to circularly polarized and linearly polarized waves in the microwave…

Classical Physics · Physics 2007-05-23 M. Encinosa , M. Jack

We obtain the distance of closest approach of the surfaces of two arbitrary ellipsoids valid at any orientation and separation, measured along their inter-center vector. This directional distance is derived from the Elliptic Contact…

Soft Condensed Matter · Physics 2009-11-11 Leonid Paramonov , S. N. Yaliraki

Measurement of the coronal magnetic field is a crucial ingredient in understanding the nature of solar coronal phenomena at all scales. We employed STEREO/COR1 data obtained during a deep minimum of solar activity in February 2008…

Solar and Stellar Astrophysics · Physics 2014-05-06 M. Kramar , V. Airapetian , Z. Mikić , J. Davila

A new equilibrium pressure profile extending the Rigid-Rotor (RR) model with a simple unified expression $P=P(\psi;\beta_{s},\alpha, \sigma)$ for both inside and outside the separatrix is proposed, in which the radial normalized…

This paper introduces a new analytical method for the determination of the coverage area modeling the Earth as an oblate ellipsoid of rotation. Starting from the knowledge of the satellite's position vector and the direction of the…

Space Physics · Physics 2019-07-01 Marco Nugnes , Camilla Colombo , Massimo Tipaldi

We shall discuss cosmological models in extended theories of gravitation. We shall define a surface, called the model surface, in the space of observable parameters which characterises families of theories. We also show how this surface can…

General Relativity and Quantum Cosmology · Physics 2016-01-21 Salvatore Capozziello , Mariafelicia F. De Laurentis , Lorenzo Fatibene , Marco Ferraris , Simon Garruto

Getting insights into the 3D structure of the solar coronal magnetic field have been done in the past by two completely different approaches: (1.) Nonlinear force-free field (NLFFF) extrapolations, which use photospheric vector magnetograms…

Solar and Stellar Astrophysics · Physics 2017-09-20 Iulia Chifu , Thomas Wiegelmann , Bernd Inhester

This paper is the third in a series of papers working towards the construction of a realistic, evolving, non-linear force-free coronal field model for the solar magnetic carpet. Here, we present preliminary results of 3D time-dependent…

Solar and Stellar Astrophysics · Physics 2013-03-07 K. A. Meyer , D. H. Mackay , A. A. van Ballegooijen , C. E. Parnell

A scalar potential model (SPM) was developed from considerations of galaxy clusters and of redshift. The SPM is applied to HI rotation curves (RCs) and RC asymmetry of spiral galaxies. The resulting model adds the force of a scalar…

Astrophysics · Physics 2007-05-23 John C. Hodge

In this paper we introduce a mathematical model for small deformations induced by external forces of closed surfaces that are minimisers of Helfrich-type energies. Our model is suitable for the study of deformations of cell membranes…

Analysis of PDEs · Mathematics 2016-10-18 Charles M. Elliott , Hans Fritz , Graham Hobbs

Seven different models are applied to the same problem of simulating the Sun's coronal magnetic field during the solar eclipse on 2015 March 20. All of the models are non-potential, allowing for free magnetic energy, but the associated…

The multipole expansion can be formulated in spherical and Cartesian coordinates. By constructing an explicit map linking both formulations in isotropic media, we discover a lack of equivalence between them in anisotropic media. In…

Let $X$ be a quadratic vector field with a center whose generic orbits are algebraic curves of genus one. To each $X$ we associate an elliptic surface (a smooth complex compact surface which is a genus one fibration). We give the list of…

Dynamical Systems · Mathematics 2008-01-29 Sebastien Gautier
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