scholarly journals CRITICISM OF "NECESSITY OF SIMULTANEOUS CO-EXISTENCE OF INSTANTANEOUS AND RETARDED INTERACTIONS IN CLASSICAL ELECTRODYNAMICS" BY CHUBYKALO AND VLAEV

2002 ◽  
Vol 17 (27) ◽  
pp. 3975-3979 ◽  
Author(s):  
J. D. JACKSON
Keyword(s):  
Electromagnetic Fields ◽  
Maxwell Equations ◽  
Electromagnetic Theory ◽  
Classical Electrodynamics ◽  
Lorentz Gauge ◽  
Vector Potentials ◽  
Electromagnetic Interactions ◽  
Derivatives Of ◽  
Made In

The demonstration that the electromagnetic fields derived from the Liénard–Wiechert potentials do not satisfy the Maxwell equations is proved to be false. Errors were made in the computation of the derivatives of retarded quantities. The subsequent inference of the necessity of both instantaneous and retarded electromagnetic interactions cannot be made. Different choices of gauge can lead to a variety of forms for the scalar and vector potentials, always with the same retarded fields. Classical electromagnetic theory is complete as usually expressed. One may choose to work in the Lorentz gauge in which all quantities are retarded.

On a duality invariant action principle in vacuum electrodynamics

1970 ◽  
Vol 48 (20) ◽  
pp. 2423-2426 ◽  
Author(s):  
G. M. Levman
Keyword(s):  
Electromagnetic Field ◽  
Electromagnetic Fields ◽  
Maxwell Equations ◽  
Lagrangian Density ◽  
Vacuum Field ◽  
Field Tensor ◽  
Field Equations ◽  
Invariant Action ◽  
Electromagnetic Field Tensor ◽  
Derivatives Of

Although Maxwell's vacuum field equations are invariant under the so-called duality rotation, the usual Lagrangian density for the electromagnetic field, which is bilinear in the first derivatives of the electromagnetic potentials, does not exhibit that invariance. It is shown that if one takes the components of the electromagnetic field tensor as field variables then the most general Lorentz invariant Lagrangian density bilinear in the electromagnetic fields and their first derivatives is determined uniquely by the requirement of duality invariance. The ensuing field equations are identical with the iterated Maxwell equations.

scholarly journals The time domain numerical method of three-dimensional conductors including radiation with lumped parameter circuit

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Souma Jinno ◽  
Shuji Kitora ◽  
Hiroshi Toki ◽  
Masayuki Abe
Keyword(s):  
Numerical Method ◽  
Time Domain ◽  
Maxwell Equations ◽  
Three Dimensional ◽  
New Formalism ◽  
Vector Potentials ◽  
Lumped Parameter ◽  
Radiation Theory ◽  
Stable Solutions ◽  
The Time Domain

AbstractWe formulate a numerical method on the transmission and radiation theory of three-dimensional conductors starting from the Maxwell equations in the time domain. We include the delay effect in the integral equations for the scalar and vector potentials rigorously, which is vital to obtain numerically stable solutions for transmission and radiation phenomena in conductors. We provide a formalism to connect the conductors to any passive lumped-parameter circuits. We show one example of numerical calculations, demonstrating that the new formalism provides stable solutions to the transmission and radiation phenomena.

scholarly journals ELECTROMAGNETIC FIELDS OF CHARGED AND MAGNETIZED CYLINDRICAL CONDUCTORS IN NUT SPACE

2005 ◽  
Vol 14 (03n04) ◽  
pp. 687-695 ◽  
Author(s):  
B. J. AHMEDOV ◽  
A. V. KHUGAEV ◽  
N. I. RAKHMATOV
Keyword(s):  
Magnetic Field ◽  
Gravitational Field ◽  
Electromagnetic Fields ◽  
Electric Charge ◽  
Maxwell Equations ◽  
Analytic Solutions ◽  
Vertical Magnetic Field ◽  
General Relativistic ◽  
Azimuthal Current ◽  
Cylindrical Conductors

We present analytic solutions of Maxwell equations for infinitely long cylindrical conductors with nonvanishing electric charge and currents in the external background spacetime of a line gravitomagnetic monopole. It has been shown that vertical magnetic field arising around cylindrical conducting shell carrying azimuthal current will be modified by the gravitational field of NUT source. We obtain that the purely general relativistic magnetic field which has no Newtonian analog will be produced around charged gravitomagnetic monopole.

scholarly journals Maxwell's Equations, Stokes' Theorem, and the Conservation of Charge

2019 ◽  
Author(s):  
Jonathan Gratus ◽  
Paul Kinsler ◽  
Martin W. McCall
Keyword(s):  
Black Holes ◽  
Effective Charge ◽  
Electromagnetic Theory ◽  
Careful Examination ◽  
Electromagnetic Excitation ◽  
Gauge Freedom ◽  
Charge Conservation ◽  
Vector Potentials ◽  
Vacuum Polarisation ◽  
A Charge

A careful examination of the fundamentals of electromagnetic theory shows that due to the underlying mathematical assumptions required for Stokes' Theorem, global charge conservation cannot be guaranteed in topologically non-trivial spacetimes. However, in order to break the charge conservation mechanism we must also allow the electromagnetic excitation fields D, H to possess a gauge freedom, just as the electromagnetic scalar and vector potentials $\varphi$ and A do. This has implications for the treatment of electromagnetism in spacetimes where black holes both form and then evaporate, as well as extending the possibilities for treating vacuum polarisation. Using this gauge freedom of D, H we also propose an alternative to the accepted notion that a charge passing through a wormhole necessarily leads to an additional (effective) charge on the wormhole's mouth.

scholarly journals Null Electromagnetic Fields from Dilatation and Rotation Transformations of the Hopfion

Symmetry ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1105 ◽  
Author(s):  
Manuel Arrayás ◽  
Antonio F. Rañada ◽  
Alfredo Tiemblo ◽  
José L. Trueba
Keyword(s):  
Electromagnetic Fields ◽  
Maxwell Equations ◽  
Symmetry Transformations ◽  
Field Lines

The application of topology concepts to Maxwell equations has led to the developing of the whole area of electromagnetic knots. In this paper, we apply some symmetry transformations to a particular electromagnetic knot, the hopfion field, to get a new set of knotted solutions with the properties of being null. The new fields are obtained by a homothetic transformation (dilatation) and a rotation of the hopfion, and we study the constraints that the transformations must fulfill in order to generate valid electromagnetic fields propagating in a vacuum. We make use of the Bateman construction and calculate the four-potentials and the electromagnetic helicities. It is observed that the topology of the field lines does not seem to be conserved as it is for the hopfion.

scholarly journals AXION-ELECTROMAGNETIC WAVES

2013 ◽  
Vol 28 (35) ◽  
pp. 1350162 ◽  
Author(s):  
LUCA VISINELLI
Keyword(s):  
Gauge Symmetry ◽  
Electromagnetic Waves ◽  
Maxwell Equations ◽  
Internal Symmetry ◽  
Classical Electrodynamics ◽  
Gauge Potential ◽  
Explicit Solutions ◽  
Duality Symmetry ◽  
Axion Field ◽  
External Sources

We extend the duality symmetry between the electric and the magnetic fields to the case in which an additional axion-like term is present, and we derive the set of Maxwell equations that preserves this symmetry. This new set of equations allows for a gauge symmetry extending the ordinary symmetry in the classical electrodynamics. We obtain explicit solutions for the new set of equations in the absence of external sources, and we discuss the implications of a new internal symmetry between the axion field and the electromagnetic gauge potential.

Protection Against Electromagnetic Fields by Means of Fractal Screen-Restructor

10.12737/2744 ◽  
2013 ◽  
Vol 20 (4) ◽  
pp. 116-120
Author(s):  
Хачапуридзе ◽  
N. Khachapuridze ◽  
Филиппов ◽  
Yu. Filippov ◽  
Соколовская ◽  
...  
Keyword(s):  
Electromagnetic Fields ◽  
High Efficiency ◽  
Three Dimensional ◽  
Small Diameter ◽  
Medical Personnel ◽  
Negative Influence ◽  
Electrically Conductive ◽  
Electromagnetic Screen ◽  
Biological Protection ◽  
Made In

To protect medical personnel and other institutions where used low- intensity electromagnetic fields the fractal electromagnetic screen-restructor was developed. This device contains a substrate of bioinert material and installation tool, which is made in the form of electromagnetic circuit, which includes overlapping concentric circles of big and small diameters and flat element located in the centre of the circle formed by the circles of the big diameter. A circle of small diameter located on six radial lines, circles of the big diameter equidistantly in relation to each other and relative to the center of the circles of the big diameter, and the flat element is made in the form of a regular hexagon. The screen was tested and has shown high efficiency. The developed fractal screen is the medical technique and is used to protect personnel from the negative influence of various fields of electro - and radio-technical installations, from unauthorized exposure, as well as for biological protection and correction of the functional state of operators industrially loaded productions. There are many devices designed for protection of an organism from the negative electromagnetic radiation, to maintain and enhance its bioenergetic potential, containing a variety of three-dimensional constructs and two-dimensional plate-a matrix, equipped with various geometric structures of electrically conductive materials, or diminutive volume elements - cylindrical or cone-shaped and their combinations.

SYMMETRY PROPERTIES OF THE EXACT EM RADIATION-REACTION EQUATION FOR CLASSICAL EXTENDED PARTICLES AND ANTIPARTICLES

2013 ◽  
Vol 28 (18) ◽  
pp. 1350086 ◽  
Author(s):  
CLAUDIO CREMASCHINI ◽  
MASSIMO TESSAROTTO
Keyword(s):  
Conservation Laws ◽  
Classical Mechanics ◽  
Finite Size ◽  
Radiation Reaction ◽  
Classical Electrodynamics ◽  
Qualitative Properties ◽  
Hamilton Variational Principle ◽  
Electromagnetic Interactions ◽  
Symmetry Properties ◽  
Self Force

Based on recent theoretical developments (Cremaschini and Tessarotto, 2011–2013), in this paper the issue is addressed of the first-principle construction of the nonlocal relativistic radiation-reaction (RR) equation for classical spherical-shell, finite-size particles and antiparticles. This is achieved invoking the axioms of Classical Electrodynamics by means of the Hamilton variational principle. In connection with this, the Lagrangian conservation laws, together with the possible existence of adiabatic invariants, and the transformation laws of the RR equation with respect to CPT and time-reversal transformations are investigated. The latter properties make possible the parametrization of the RR equations, holding respectively for particles and antiparticles of this type, in terms of the same coordinate time t and the investigation of the qualitative properties of their solutions. In particular, in both cases the RR self-force is found to have the same signature, which implies that the dynamics of classical finite-size antiparticles is equivalent to that of classical extended particles of opposite charge. Therefore, in the framework of Classical Mechanics, a distinction between particles and antiparticles cannot be made based solely on the electromagnetic interactions associated with electromagnetic RR phenomena. As a basic application of the theory, the Lagrangian conservation laws and symmetry properties for the Hamiltonian asymptotic approximations of the exact RR equation are also addressed.

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