101.
Generación y medición de un campo electromagnético uniforme / Corrado Vitale, Ch
- Vitale Ch., Corrado; Universidad de Los Andes.. Facultad de Ingeniería., Trabajo de ascenso, 1987
Material mecanografiado
102.
K -> pi pi Phenomenology in the Presence of Electromagnetism
- Cirigliano, Vincenzo; Donoghue, John F.; Golowich, Eugene
We describe the influence of electromagnetism on the phenomenology of K -> pi
pi decays. This is required because the present data were analyzed without
inclusion of electromagnetic radiative corrections, and hence contain several
ambiguities and uncertainties which we describe in detail. Our presentation
includes a full description of the infrared effects needed for a new
experimental analysis. It also describes the general treatment of final state
interaction phases, needed because Watson's theorem is no longer valid in the
presence of electromagnetism. The phase of the isospin-two amplitude A_2 may be
modified by 50% -> 100%. We provide a tentative analysis using present data in
order to illustrate the...
103.
Potential Momentum, Gauge Theory, and Electromagnetism in Introductory
Physics
- Raymond, David J.
If potential energy is the timelike component of a four-vector, then there
must be a corresponding spacelike part which would logically be called the
potential momentum. The potential four-momentum consisting of the potential
momentum and the potential energy taken together is just the gauge field of the
associated force times the charge associated with that force. The canonical
momentum is the sum of the ordinary and potential momenta. Refraction of matter
waves by a discontinuity in a gauge field can be used to explore the effects of
gauge fields at an elementary level. Using this tool it is possible to show how
the Lorentz force law of electromagnetism...
104.
A hybrid scatter search / electromagnetism meta-heuristic for project scheduling
- Dieter Debels; Bert de Reyck; Roel Leus; Mario Vanhoucke
In the last few decades, several effective algorithms for solving the resource-constrained project scheduling problem have been proposed. However, the challenging nature of this problem, summarised in its strongly NP-hard status, restricts the effectiveness of exact optimisation to relatively small instances. In this paper, we present a new meta-heuristic for this problem, able to provide near-optimal heuristic solutions. The procedure combines elements from scatter search, a generic population-based evolutionary search method, and a recently introduced heuristic method for the optimisation of unconstrained continuous functions based on an analogy with electromagnetism theory, hereafter referred to as the electromagnetism meta-heuristic. We present...
105.
A Hybrid Scatter Search / Electromagnetism Meta-Heuristic for Project Scheduling
- D. DEBELS; B. DE REYCK; R. LEUS; M. VANHOUCKE
In the last few decades, several effective algorithms for solving the resource-constrained project scheduling problem have been proposed. However, the challenging nature of this problem, summarised in its strongly NP-hard status, restricts the effectiveness of exact optimisation to relatively small instances. In this paper, we present a new meta-heuristic for this problem, able to provide near-optimal heuristic solutions. The procedure combines elements from scatter search, a generic population-based evolutionary search method, and a recently introduced heuristic method for the optimisation of unconstrained continuous functions based on an analogy with electromagnetism theory, hereafter referred to as the electromagnetism meta-heuristic. We present...
106.
Negative Refraction and Left-handed electromagnetism in Microwave
Photonic Crystals
- Parimi, P. V.; Lu, W. T.; Vodo, P.; Sokoloff, J.; Sridhar, S.
We demonstrate negative refraction of microwaves in metallic photonic
crystals. The spectral response of the photonic crystal, which manifests both
positive and negative refraction, is in complete agreement with band-structure
calculations and numerical simulations. The negative refraction observed
corresponds to left-handed electromagnetism and arises due to the dispersion
characteristics of waves in a periodic medium. This mechanism for negative
refraction is different from that in metamaterials.
107.
On the analogy between electromagnetism and turbulent hydrodynamics
- Marmanis, Haralambos
In this note, we propose an exegesis of the Maxwell equations for
electromagnetism. We begin with an analogy between the homogeneous Maxwell
equations and the equations needed to describe the vorticity field of an
incompressible inviscid fluid. We suggest that the inhomogeneous equations are
analogous to two equations valid in turbulent hydrodynamics. Once the analogy
is completed we give the mechanical analogue of the Poynting vector and we
explain the influence of a long solenoid on the motion of a charged particle.
108.
The Born-Infeld electromagnetism in Kaluza-Klein theory
- Lemos, José P. S.; Kerner, Richard
We investigate the properties of non-linear electromagnetism based on the
Born-Infeld Lagrangian in multi-dimensional theories of Kaluza-Klein type. We
consider flat space-time solutions only, which means that the space-time metric
is constant, and the only supplementary variable is the dilaton field, a
scalar. We show that in the case of Kaluza-Klein theory, the Born-Infeld
Lagrangian describes an interesting interaction between the electromagnetic and
scalar fields, whose propagation properties are modified in a non-trivial
manner.
109.
General Relativistic Electromagnetism and Particle Acceleration in
Pulsar Polar Cap
- Sakai, Nobuyuki; Shibata, Shinpei
We reconstruct a 3+1 formalism of general relativistic electromagnetism, and
derive the equations of motion of charged particles in the pulsar
magnetosphere, taking account of the inclination between the rotation axis and
the magnetic axis. Apart from the previous works where space charge is
evaluated by assuming the flow velocity being the light speed, we analyze
particle motion in the polar cap, finding that gravity changes significantly
its dynamics and the condition for acceleration.
110.
Symmetries of the equations of pre-metric electromagnetism
- Delphenich, David
The equations of pre-metric electromagnetism are summarized and then
formulated as an exterior differential system on the total space of the bundle
of 2-forms over the spacetime manifold. The Harrison-Estabrook method of
computing the symmetries of the system is then applied, with the result that of
the four possible formal algebras of infinitesimal symmetries, the most
physically compelling one is the Lie algebra of infinitesimal projective
transformations of real four-dimensional projective space.
111.
Unification of Electromagnetism and Gravitation in the Framework of
General Geometry
- Shahverdiyev, Shervgi
A new geometry, called General geometry, is constructed. It is proven that
its the most simplest special case is geometry underlying Electromagnetism.
Another special case is Riemannian geometry. Action for electromagnetic field
and Maxwell equations are derived from curvature function of geometry
underlying Electromagnetism. It is shown that equation of motion for a particle
interacting with electromagnetic field coincides exactly with equation for
geodesics of geometry underlying Electromagnetism. It is also shown that
Electromagnetism can not be geometrized in the framework of Riemannian
geometry. Using General Geometry we propose a unified model of electromagnetism
and gravitation which reproduces Electromagnetism and Gravitation and predicts
that electromagnetic field is a source for...
112.
Watson's theorem and electromagnetism in K -> pi pi decay
- Gardner, S.; Meißner, Ulf-G.; Valencia, G.
We consider what constraints unitarity and CPT invariance yield on the strong
and electromagnetic phases entering K -> pi pi decay. In particular, we show
that the relative size of the electromagnetically-induced changes in the I=0
and I=2 phase shifts in the two--pion final state do not depend on the explicit
coupling to the pi^+ pi^- gamma channel. This demonstrates that Watson's
theorem can be extended to include the presence of electromagnetism. We point
out the consequences for the general structure of the K -> pi pi decay
amplitudes in the presence of isospin violation.
113.
Coupling gravity, electromagnetism and space-time for space propulsion breakthroughs
- Millis, Marc G.
spaceflight would be revolutionized if it were possible to propel a spacecraft without rockets using the coupling between gravity, electromagnetism, and space-time (hence called 'space coupling propulsion'). New theories and observations about the properties of space are emerging which offer new approaches to consider this breakthrough possibility. To guide the search, evaluation, and application of these emerging possibilities, a variety of hypothetical space coupling propulsion mechanisms are presented to highlight the issues that would have to be satisfied to enable such breakthroughs. A brief introduction of the emerging opportunities is also presented.
114.
Failure of geometric electromagnetism in the adiabatic vector Kepler
problem
- Anglin, J. R.; Schmiedmayer, J.
The magnetic moment of a particle orbiting a straight current-carrying wire
may precess rapidly enough in the wire's magnetic field to justify an adiabatic
approximation, eliminating the rapid time dependence of the magnetic moment and
leaving only the particle position as a slow degree of freedom. To zeroth order
in the adiabatic expansion, the orbits of the particle in the plane
perpendicular to the wire are Keplerian ellipses. Higher order post-adiabatic
corrections make the orbits precess, but recent analysis of this `vector Kepler
problem' has shown that the effective Hamiltonian incorporating a
post-adiabatic scalar potential (`geometric electromagnetism') fails to predict
the precession correctly, while a heuristic alternative succeeds. In...
115.
Coupling of Gravitation and Electromagnetism in the Weak Field
Approximation
- Tajmar, M.; de Matos, C.
Using the weak field approximation, we can express the theory of general
relativity in a Maxwell-type structure comparable to electromagnetism. We find
that every electromagnetic field is coupled to a gravitoelectric and
gravitomagnetic field. Acknowledging the fact that both fields originate from
the same source, the particle, we can express the magnetic and electric field
through their gravitational respective analogues using the proportionality
coefficient k. This coefficient depends on the ratio of mass and charge and the
ratio between the electromagnetic and gravitic-gravitomagnetic permittivity and
permeability respectively. Although the coefficient is very small, the fact
that electromagnetic fields in material media can be used to generate
gravitational and gravitomagnetic fields...
116.
Electromagnetism and Gauge Theory on the Permutation Group $S_3$
- Majid, Shahn; Raineri, E.
Using noncommutative geometry we do U(1) gauge theory on the permutation
group $S_3$. Unlike usual lattice gauge theories the use of a nonAbelian group
here as spacetime corresponds to a background Riemannian curvature. In this
background we solve spin 0, 1/2 and spin 1 equations of motion, including the
spin 1 or `photon' case in the presence of sources, i.e. a theory of classical
electromagnetism. Moreover, we solve the U(1) Yang-Mills theory (this differs
from the U(1) Maxwell theory in noncommutative geometry), including the moduli
spaces of flat connections. We show that the Yang-Mills action has a simple
form in terms of Wilson loops in the permutation group,...
117.
Historical Note on the Relativistic Theories of Electromagnetism
- Dvoeglazov, Valeri V.
Quantum electrodynamics is the well-accepted theory. However, we feel it is
useful to look at formalisms that provide alternative ways to describe light,
because in the recent years the development of quantum field theories based
primarily on the gauge principle has encountered considerable difficulties.
There is a wide variety of generalized theories and they are characterized
mainly by the introduction of additional parameters and/or longitudinal modes
of electromagnetism. The Majorana-Oppenheimer form of electrodynamics, the
Sachs' theory of Elementary Matter, the analysis of the action-at-a-distance
concept, presented recently by Chubykalo and Smirnov-Rueda, and the analysis of
the claimed `longitudinality' of the antisymmetric tensor field after
quantization are reviewed in this essay....
118.
Large-scale magnetic fields from inflation in dilaton electromagnetism
- Bamba, Kazuharu; Yokoyama, J.
The generation of large-scale magnetic fields is studied in dilaton
electromagnetism in inflationary cosmology, taking into account the dilaton's
evolution throughout inflation and reheating until it is stabilized with
possible entropy production. It is shown that large-scale magnetic fields with
observationally interesting strength at the present time could be generated if
the conformal invariance of the Maxwell theory is broken through the coupling
between the dilaton and electromagnetic fields in such a way that the resultant
quantum fluctuations in the magnetic field has a nearly scale-invariant
spectrum. If this condition is met, the amplitude of the generated magnetic
field could be sufficiently large even in the case huge amount...
119.
On the origin dependence of multipole moments in electromagnetism
- De Visschere, Patrick
The standard description of material media in electromagnetism is based on
multipoles. It is well known that these moments depend on the point of
reference chosen, except for the lowest order. It is shown that this "origin
dependence" is not unphysical as has been claimed in the literature but forms
only part of the effect of moving the point of reference. When also the
complementary part is taken into account then different points of reference
lead to different but equivalent descriptions of the same physical reality.
This is shown at the microscopic as well as at the macroscopic level. A similar
interpretation is valid regarding the "origin dependence"...
120.
The affine theory of gravitation and electromagnetism I
- Poplawski, Nikodem J.
The affine variational principle of Eddington generates the Einstein field
equations of general relativity in vacuum with a non-zero cosmological
constant. We generalize this principle to include electromagnetism, obtaining
the Einstein-Maxwell field equations and the Lorentz equation of motion. We
vary the action with respect to the quantities that appear in the definition of
the electromagnetic covariant derivative: the affine (nonsymmetric) connection
and the electromagnetic potential, while the Lagrangian density is taken to be
the square root of the determinant of a linear combination of the symmetrized
Ricci tensor and the electromagnetic field tensor. This construction generates
a symmetric metric tensor and a connection with torsion that depends only...
