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Based on a decomposition of the magnetic field into potential and nonpotential components, magnetic energy and relative helicity can both also be decomposed into two quantities: potential and free energies, and volume-threading and…

Solar and Stellar Astrophysics · Physics 2020-04-15 Luis Linan , Étienne Pariat , Guillaume Aulanier , Kostas Moraitis , Gherardo Valori

By means of the rotational transformations of octonion coordinate systems, the paper aims to explore the physical properties of conserved quantities relevant to the vectorial magnitudes within the material media, revealing the simultaneity…

General Physics · Physics 2023-02-22 Zi-Hua Weng

We calculate analytically the spin-orbital decomposition of the angular momentum using completely non-paraxial fields that have certain degree of linkage of electric and magnetic lines. The split of the angular momentum into spin-orbital…

Optics · Physics 2018-09-26 M Arrayás , J L Trueba

Fluxes of the magnetic helicity density play an important role in large-scale turbulent dynamos, allowing the growth of large-scale magnetic fields while overcoming catastrophic quenching. We show here, analytically, how several important…

Astrophysics of Galaxies · Physics 2023-01-27 Kishore Gopalakrishnan , Kandaswamy Subramanian

We study the Poincar\'e gauge theory of gravity with the most general Lagrangian quadratic in curvature and torsion, focusing on the possible interaction of the axial torsion with the electromagnetic field. From the analysis of the closed…

General Relativity and Quantum Cosmology · Physics 2024-10-03 Mariya Iv. Trukhanova , Yu. N. Obukhov

It is shown that the turbulent dynamo $\alpha$-effect converts magnetic helicity from the turbulent field to the mean field when the turbulence is electromagnetic while the magnetic helicity of the mean-field is transported across space…

Astrophysics · Physics 2008-11-26 Hantao Ji

When neutrinos propagate in a background, their gravitational couplings are modified by their weak interactions with the particles in the background. In a medium that contains electrons but no muons or taons, the matter-induced…

High Energy Physics - Phenomenology · Physics 2010-12-03 H. Athar , Jose F. Nieves

In strongly compressible magnetohydrodynamic turbulence, obliqueness between the large-scale density gradient and magnetic field gives an electromotive force mediated by density variance (intensity of density fluctuation). This effect is…

Solar and Stellar Astrophysics · Physics 2022-05-31 Nobumitsu Yokoi , Steven M. Tobias

We study the conserved quantity associated with the dual symmetry of the Maxwell equations, called the optical helicity, by means of transverse Hertz vectors. In the presence of charges, its evolution yields the integral of…

Optics · Physics 2018-05-29 Mahmut Elbistan

In the paper [4] is presented a theory which unifies the gravitation theory and the mechanical effects, which is different from the Riemannian theories like GTR. Moreover it is built in the style of the electomagnetic field theory. This…

Differential Geometry · Mathematics 2007-05-23 Kostadin Trencevski

The matrix elements of the electromagnetic current and the energy-momentum tensor for sharply localized states of spin-1 systems are considered. Their interpretation as local spatial densities of various characteristics of the considered…

High Energy Physics - Phenomenology · Physics 2023-08-16 J. Yu. Panteleeva , E. Epelbaum , J. Gegelia , U. -G. Meißner

Magnetic helicity is a fundamental quantity of magnetohydrodynamics that carries topological information about the magnetic field. By `topological information', we usually refer to the linkage of magnetic field lines. For domains that are…

Plasma Physics · Physics 2019-09-25 David MacTaggart , Alberto Valli

We calculate the atomic structure of hydrogen and helium, atoms and molecules in an intense magnetic field, analytically and numerically with a judiciously chosen basis.

Atomic Physics · Physics 2009-10-31 Jeremy S. Heyl , Lars Hernquist

Based on investigations of the fundamental properties of the generalized Einstein Lagrangian density for a gravitational system, the theoretical foundations of the modified Einstein field equations and the Lorentz and Levi-Civita…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Fang-Pei Chen

Helicity is a property of light which is familiar from particle physics but less well-known in optics. In this paper we recall the explicit form taken by the helicity of light within classical electromagnetic theory and reflect upon some of…

Optics · Physics 2015-06-16 Robert P. Cameron , Stephen M. Barnett , Alison M. Yao

To explore the potential role of gravity, turbulence and magnetic fields in high-mass star formation in molecular clouds, this study revisits the velocity dispersion--size ($\sigma$--$L$) and density--size ($\rho$--$L$) scalings and the…

Astrophysics of Galaxies · Physics 2024-05-09 An-Xu Luo , Hong-Li Liu , Guang-Xing Li , Sirong Pan , Dong-Ting Yang

The average helicity of a given electromagnetic field measures the difference between the number of left- and right-handed photons contained in the field. In here, the average helicity is derived using the conformally-invariant…

Optics · Physics 2019-11-21 Ivan Fernandez-Corbaton

Topological implications of the total generalized electron-flow magnetic helicity He in electron magnetohydrodynamics(EMHD) are explored. The invariance of He is shown to imply the invariance of the sum of the linkage of the magnetic field…

Plasma Physics · Physics 2019-05-01 B. K. Shivamoggi , M. Michalak

In my lectures I will deal with three seemingly unrelated problems: i) to what extent is general relativity exceptional among metric gravity theories? ii) is it possible to define gravitational energy density applying field-theory approach…

General Relativity and Quantum Cosmology · Physics 2016-08-14 Leszek M. Sokołowski

The hypermagnetic helicity density at the electroweak phase transition (EWPT) exceeds many orders of magnitude the galactic magnetic helicity density. Together with previous magnetic helicity evolution calculations after the EWPT and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 V. B. Semikoz , D. Sokoloff , J. W. F. Valle