61.
A Connection between Gravitation and Electromagnetism
- Snyder, D. M.
It is argued that there is a connection between the fundamental forces of
electromagnetism and gravitation. This connection occurs because of: 1) the
fundamental significance of the finite and invariant velocity of light in
inertial reference frames in the special theory, and 2) the reliance of the
general theory of relativity upon the special theory of relativity locally in
spacetime. The connection between the fundamental forces of electromagnetism
and gravitation follows immediately from these two points. A brief review is
provided of: 1) the role of the finite and invariant velocity of light in
inertial reference frames in the special theory, and 2) certain fundamental
concepts of the general...
62.
Space-Time Structure and Electromagnetism
- Wanas, M. I.; Ammar, S. A.
Two Lagrangian functions are used to construct geometric field theories. One
of these Lagrangians depends on the conventional curvature of space, while the
other depends on curvature and torsion. It is shown that the theory constructed
from the first Lagrangian gives rise to pure gravity, while the theory
constructed using the second Lagrangian gives rise to both gravity and
electromagnetism. The two theories are constructed in a version of absolute
parallelism geometry in which both curvature and torsion are, simultaneously,
non-vanishing. One single geometric object, {\it the non-conventional curvature
tensor}, reflecting the properties of curvature and torsion, is defined in this
version and is used to construct the second...
63.
On Degenerate Metrics and Electromagnetism
- Searight, T. P.
A theory of degenerate metrics is developed and applied to the problem of
unifying gravitation with electromagnetism. The approach is similar to the
Kaluza-Klein approach with a fifth dimension, however no ad hoc conditions are
needed to explain why the extra dimension is not directly observable under
everyday conditions. Maxwell's theory is recovered with differences only at
very small length scales, and a new formula is found for the Coulomb potential
that is regular everywhere.
64.
Black Hole Thermodynamics and Electromagnetism
- Sidharth, Burra G.
We show a strong parallel between the Hawking, Beckenstein black hole
Thermodynamics and electromagnetism: When the gravitational coupling constant
transform into the electromagnetic coupling constant, the Schwarzchild radius,
the Beckenstein temperature, the Beckenstein decay time and the Planck mass
transform to respectively the Compton wavelength, the Hagedorn temperature, the
Compton time and a typical elementary particle mass. The reasons underlying
this parallalism are then discussed in detail.
65.
On the completeness of classical electromagnetism
- Minotti, Fernando O.
The possibility of an incompletness of the equations of electromagnetism is
analyzed using a thought experiment that shows a non-physical behavior
according to classical electromagnetism. Basically, from Maxwell equations it
is shown that a particular passive, isolated circuit could present a transient
growth of its currents. Resolution of this problem is sought within the context
of the usual electromagnetism and also using the possibly simplest
generalization of Maxwell equations, a reduced version of Ohmura equations.
66.
Analog Electromagnetism in a Symmetrized $^3$He-A
- Dziarmaga, Jacek
We derive a low temperature effective action for the order parameter in a
symmetrized phase A of helium 3, where the Fermi velocity equals the
transversal velocity of low energy fermionic quasiparticles. The effective
action has a form of the electromagnetic action. This analog electromagnetism
is a part of the program to derive analog gravity and the standard model as a
low energy effective theory in a condensed matter system. For the analog gauge
field to satisfy the Maxwell equations interactions in $^3$He require special
tuning that leads to the symmetric case.
67.
Spinors and pre-metric electromagnetism
- Delphenich, David
The basic concepts of the formulation of Maxwellian electromagnetism in the
absence of a Minkowski scalar product on spacetime are summarized, with
particular emphasis on the way that the electromagnetic constitutive law on the
space of bivectors over spacetime supplants the role of the Minkowski scalar
product on spacetime itself. The complex geometry of the space of bivectors is
summarized, with the intent of showing how an isomorphic copy of the Lorentz
group appears in that context. The use of complex 3-spinors to represent
electromagnetic fields is then discussed, as well as the expansion of scope
that the more general complex projective geometry of the space of bivectors
suggests.
68.
Duality in Off-Shell Electromagnetism
- Land, Martin
In this paper, we examine the Dirac monopole in the framework of Off-Shell
Electromagnetism, the five dimensional U(1) gauge theory associated with
Stueckelberg-Schrodinger relativistic quantum theory. After reviewing the Dirac
model in four dimensions, we show that the structure of the five dimensional
theory prevents a natural generalization of the Dirac monopole, since the
theory is not symmetric under duality transformations. It is shown that the
duality symmetry can be restored by generalizing the electromagnetic field
strength to an element of a Clifford algebra. Nevertheless, the generalized
framework does not permit us to recover the phenomenological (or conventional)
absence of magnetic monopoles.
69.
Electromagnetism
- Frank N. H.; Slater J. C.
70.
Electromagnetismo
- Oseguera, Urbano
71.
Electromagnetism
- Pollack, Gerald L.; Stump, Daniel R.
0-8053-8567-3
72.
Electromagnetismo
- Edminister, Joseph A.
970-10-0256-3
73.
Electromagnétisme
- GARDIOL, Fréderic
74.
Electromagnétisme
- VITTOZ, Bernard
75.
Gauge Symmetry and Gravito-Electromagnetism
- Clark, Simon J.; Tucker, Robin W.
A tensor description of perturbative Einsteinian gravity about an arbitrary
background spacetime is developed. By analogy with the covariant laws of
electromagnetism in spacetime, gravito-electromagnetic potentials and fields
are defined to emulate electromagnetic gauge transformations under
substitutions belonging to the gauge symmetry group of perturbative
gravitation. These definitions have the advantage that on a flat background,
with the aid of a covariantly constant timelike vector field, a subset of the
linearised gravitational field equations can be written in a form that is fully
analogous to Maxwell's equations (without awkward factors of 4 and extraneous
tensor fields). It is shown how the remaining equations in the perturbed
gravitational system restrict the...
76.
Symmetries and pre-metric electromagnetism
- Delphenich, David
The equations of pre-metric electromagnetism are formulated as an exterior
differential system on the bundle of exterior differential 2-forms over the
spacetime manifold. The general form for the symmetry equations of the system
is computed and then specialized to various possible forms for an
electromagnetic constitutive law, namely, uniform linear, non-uniform linear,
and uniform nonlinear. It is shown that in the uniform linear case, one has
four possible ways of prolonging the symmetry Lie algebra, including
prolongation to a Lie algebra of infinitesimal projective transformations of a
real four-dimensional projective space. In the most general non-uniform linear
case, th effect of non-uniformity on symmetry seems inconclusive in the absence
of...
77.
Two Controversies in Classical Electromagnetism
- Pfeifer, R. N. C.; Nieminen, T. A.; Heckenberg, N. R.; Rubinsztein-Dunlop, H.
This paper examines two controversies arising within classical electromagnetism which are relevant to the optical trapping and micromanipulation community. First is the Abraham-Minkowski controversy, a debate relating to the form of the electromagnetic energy momentum tensor in dielectric materials, with implications for the momentum of a photon in dielectric media. A wide range of alternatives exist, and experiments are frequently proposed to attempt to discriminate between them. We explain the resolution of this controversy and show that regardless of the electromagnetic energy momentum tensor chosen, when material disturbances are also taken into account the predicted behaviour will always be the...
78.
Gravity and Electromagnetism in Noncommutative Geometry
- Landi, Giovanni; Viet, Nguyen Ai; Wali, Kameshwar C.
We present a unified description of gravity and electromagnetism in the
framework of a $Z_2$ noncommutative differential calculus. It can be considered
as a ``discrete version" of Kaluza-Klein theory, where the fifth continuous
dimension is replaced by two discrete points. We derive an action which
coincides with the dimensionally reduced one of the ordinary Kaluza-Klein
theory.
79.
Gravitation as a weak electromagnetism and other issues
- Sidharth, B. G.
In the context of a Planck scale underpinning for the universe, we argue that
both gravitation and electromagnetism can be characterized in a unified way, in
a Sakharov like description. We also consider the issue of observed gamma
radiation, which recent observations seem to indicate are caused by the
annihilation of exotic $Mev$ particles, as indeed was theoretically predicted
earlier. Some other problems are also considered.
80.
Information Technology Used for Teaching Electromagnetism
- Soares, Antonio J.M.; Abdalla, H.; Carvalho, Paulo de; Menezes, Leonardo de; Silva, Franklin da C.; Pastor, Eduardo T.L.
Este trabajo trata sobre la elaboración de un ambiente multimedia destinado a la enseñanza de electromagnetismo aplicado. El material está constituido por un tutorial electrónico sobre sistemas radiantes, por video-streams y por un CAD, en el cual pueden ser desarrollados proyectos de enlaces de microondas. El tutorial electrónico, desarrollado en ambiente Authorware 4, contiene textos, imágenes y animaciones que buscan dar, al usuario, una visión general sobre tópicos importantes de la teoría electromagnética aplicada. Utilizando la técnica de videoconferencia fueron desarrollados video-streams asociados a cada uno de los principales tópicos abordados. A partir del tutorial es posible accesar el CAD...
