Electromagnetism and special relativity

2018 ◽  
Author(s):  
J. Pierrus
Keyword(s):  
Electromagnetic Field ◽  
Special Relativity ◽  
Point Charge ◽  
Reference Frames ◽  
Classical Electrodynamics ◽  
Covariant Form ◽  
Field Tensor ◽  
Electromagnetic Field Tensor ◽  
Preferred Reference Frame ◽  
Physical Quantities

In 1905, when Einstein published his theory of special relativity, Maxwell’s work was already about forty years old. It is therefore both remarkable and ironic (recalling the old arguments about the aether being the ‘preferred’ reference frame for describing wave propagation) that classical electrodynamics turned out to be a relativistically correct theory. In this chapter, a range of questions in electromagnetism are considered as they relate to special relativity. In Questions 12.1–12.4 the behaviour of various physical quantities under Lorentz transformation is considered. This leads to the important concept of an invariant. Several of these are encountered, and used frequently throughout this chapter. Other topics considered include the transformationof E- and B-fields between inertial reference frames, the validity of Gauss’s law for an arbitrarily moving point charge (demonstrated numerically), the electromagnetic field tensor, Maxwell’s equations in covariant form and Larmor’s formula for a relativistic charge.

scholarly journals A class of solitons in Maxwell-scalar and Einstein–Maxwell-scalar models

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Carlos A. R. Herdeiro ◽  
João M. S. Oliveira ◽  
Eugen Radu
Keyword(s):  
Electromagnetic Field ◽  
Scalar Field ◽  
Quantum Gravity ◽  
Exact Solutions ◽  
Point Charge ◽  
Coulomb Field ◽  
Specific Class ◽  
Minimal Coupling ◽  
Flat Spacetime ◽  
Physical Quantities

AbstractRecently, no-go theorems for the existence of solitonic solutions in Einstein–Maxwell-scalar (EMS) models have been established (Herdeiro and Oliveira in Class Quantum Gravity 36(10):105015, 2019). Here we discuss how these theorems can be circumvented by a specific class of non-minimal coupling functions between a real, canonical scalar field and the electromagnetic field. When the non-minimal coupling function diverges in a specific way near the location of a point charge, it regularises all physical quantities yielding an everywhere regular, localised lump of energy. Such solutions are possible even in flat spacetime Maxwell-scalar models, wherein the model is fully integrable in the spherical sector, and exact solutions can be obtained, yielding an explicit mechanism to de-singularise the Coulomb field. Considering their gravitational backreaction, the corresponding (numerical) EMS solitons provide a simple example of self-gravitating, localised energy lumps.

scholarly journals Toward Nonlocal Electrodynamics of Accelerated Systems

Universe ◽  
2020 ◽  
Vol 6 (12) ◽  
pp. 229
Author(s):  
Bahram Mashhoon
Keyword(s):  
Electromagnetic Field ◽  
Parity Violation ◽  
Spin Rotation ◽  
Field Tensor ◽  
Parity Conservation ◽  
Electromagnetic Field Tensor ◽  
Nonlocal Electrodynamics

We revisit acceleration-induced nonlocal electrodynamics and the phenomenon of photon spin-rotation coupling. The kernel of the theory for the electromagnetic field tensor involves parity violation under the assumption of linearity of the field kernel in the acceleration tensor. However, we show that parity conservation can be maintained by extending the field kernel to include quadratic terms in the acceleration tensor. The field kernel must vanish in the absence of acceleration; otherwise, a general dependence of the kernel on the acceleration tensor cannot be theoretically excluded. The physical implications of the quadratic kernel are briefly discussed.

scholarly journals THE SELF-FORCE OF A CHARGED PARTICLE IN CLASSICAL ELECTRODYNAMICS WITH A CUTOFF

1999 ◽  
Vol 13 (03) ◽  
pp. 315-324 ◽  
Author(s):  
J. FRENKEL ◽  
R. B. SANTOS
Keyword(s):  
Charged Particle ◽  
Special Relativity ◽  
Point Charge ◽  
Equation Of Motion ◽  
The Self ◽  
Classical Electrodynamics ◽  
Exact Equation ◽  
Electromagnetic Mass ◽  
Self Force

We discuss, in the context of classical electrodynamics with a Lorentz invariant cutoff at short distances, the self-force acting on a point charged particle. It follows that the electromagnetic mass of the point charge occurs in the equation of motion in a form consistent with special relativity. We find that the exact equation of motion does not exhibit runaway solutions or non-causal behavior, when the cutoff is larger than half of the classical radius of the electron.

scholarly journals THE MAXWELL LAGRANGIAN IN PURELY AFFINE GRAVITY

2008 ◽  
Vol 23 (03n04) ◽  
pp. 567-579 ◽  
Author(s):  
NIKODEM J. POPŁAWSKI
Keyword(s):  
Electromagnetic Field ◽  
Ricci Tensor ◽  
Maxwell Equations ◽  
Legendre Transformation ◽  
Conformal Transformations ◽  
Field Tensor ◽  
Metric Tensor ◽  
Hamiltonian Density ◽  
Electromagnetic Field Tensor ◽  
Affine Gravity

The purely affine Lagrangian for linear electrodynamics, that has the form of the Maxwell Lagrangian in which the metric tensor is replaced by the symmetrized Ricci tensor and the electromagnetic field tensor by the tensor of homothetic curvature, is dynamically equivalent to the Einstein–Maxwell equations in the metric–affine and metric formulation. We show that this equivalence is related to the invariance of the Maxwell Lagrangian under conformal transformations of the metric tensor. We also apply to a purely affine Lagrangian the Legendre transformation with respect to the tensor of homothetic curvature to show that the corresponding Legendre term and the new Hamiltonian density are related to the Maxwell–Palatini Lagrangian for the electromagnetic field. Therefore the purely affine picture, in addition to generating the gravitational Lagrangian that is linear in the curvature, justifies why the electromagnetic Lagrangian is quadratic in the electromagnetic field.

ON THE RELATIVISTIC THEORY OF CHARGE

1993 ◽  
Vol 07 (06) ◽  
pp. 413-419
Author(s):  
Y. AKTAS ◽  
M. W. EVANS ◽  
F. FARAHI
Keyword(s):  
Electromagnetic Field ◽  
Experimental Observation ◽  
Linear Relation ◽  
Relativistic Theory ◽  
Qualitative Agreement ◽  
Point Charge ◽  
Reference Frames ◽  
Speed Of Light ◽  
Scalar Parameter ◽  
Vector Potentials

The concept of charge is developed relativistically by assuming that there is a linear relation between point charge (e) and point mass (m) of the type: [Formula: see text] where ζ is a scalar parameter which is unchanged in all reference frames. The theory shows that charge, in a relativistic development based on this hypothesis, depends in general on the velocity of the particle carrying the charge, and the latter vanishes at the speed of light. The hypothesis (1) also implies that charge depends on the scalar and vector potentials of the electromagnetic field. These conclusions are in qualitative agreement with experimental observation.

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 Answering Mermin’s challenge with conservation per no preferred reference frame

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
W. M. Stuckey ◽  
Michael Silberstein ◽  
Timothy McDevitt ◽  
T. D. Le
Keyword(s):  
Special Relativity ◽  
Reference Frame ◽  
Reference Frames ◽  
Relativistic Quantum ◽  
Symmetry Plane ◽  
Real Space ◽  
Relativistic Quantum Mechanics ◽  
General Reader ◽  
Famous Paper ◽  
Preferred Reference Frame

Abstract In 1981, Mermin published a now famous paper titled, “Bringing home the atomic world: Quantum mysteries for anybody” that Feynman called, “One of the most beautiful papers in physics that I know.” Therein, he presented the “Mermin device” that illustrates the conundrum of quantum entanglement per the Bell spin states for the “general reader.” He then challenged the “physicist reader” to explain the way the device works “in terms meaningful to a general reader struggling with the dilemma raised by the device.” Herein, we show how “conservation per no preferred reference frame (NPRF)” answers that challenge. In short, the explicit conservation that obtains for Alice and Bob’s Stern-Gerlach spin measurement outcomes in the same reference frame holds only on average in different reference frames, not on a trial-by-trial basis. This conservation is SO(3) invariant in the relevant symmetry plane in real space per the SU(2) invariance of its corresponding Bell spin state in Hilbert space. Since NPRF is also responsible for the postulates of special relativity, and therefore its counterintuitive aspects of time dilation and length contraction, we see that the symmetry group relating non-relativistic quantum mechanics and special relativity via their “mysteries” is the restricted Lorentz group.

THE DYNAMICAL THEORY OF MAGNETIC MONOPOLES

1952 ◽  
Vol 30 (3) ◽  
pp. 218-225 ◽  
Author(s):  
S. Shanmugadhasan
Keyword(s):  
Electromagnetic Field ◽  
Equations Of Motion ◽  
Natural Generalization ◽  
Magnetic Monopoles ◽  
Dynamical Theory ◽  
The Other ◽  
Field Tensor ◽  
Physical Content ◽  
Electromagnetic Field Tensor ◽  
Set Up

The theory of electric charges and magnetic monopoles has been set up by Dirac by expressing the electromagnetic field tensor in terms of one four-potential and of the variables describing the strings attached to each magnetic mono-pole. In this reformulation of Dirac's theory the field tensor is expressed in terms of two four-potentials, one corresponding to charges and the other to monopoles, and the action principle for the equations of motion is set up in terms of the two four-potentials and of the tensors dual to them. Thus there is formal symmetry as far as is possible in the treatment of the charges and the monopoles. Also the mathematics is direct and neat. Though the physical content is the same as that of Dirac, a natural generalization of the Fermi form of electrodynamics subject to the restriction that the same particle cannot have both charge and monopole is obtained here.

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