717 research outputs found
Hypothesis of path integral duality: Applications to QED
We use the modified propagator for quantum field based on a ``principle of
path integral duality" proposed earlier in a paper by Padmanabhan to
investigate several results in QED. This procedure modifies the Feynman
propagator by the introduction of a fundamental length scale. We use this
modified propagator for the Dirac particles to evaluate the first order
radiative corrections in QED. We find that the extra factor of the modified
propagator acts like a regulator at the Planck scales thereby removing the
divergences that otherwise appear in the conventional radiative correction
calculations of QED. We find that:(i) all the three renormalisation factors
, , and pick up finite corrections and (ii) the modified
propagator breaks the gauge invariance at a very small level of
. The implications of this result to generation of the
primordial seed magnetic fields are discussed.Comment: 15 pages, LaTeX2e (uses ijmpd.sty); To appear in IJMP-D; References
adde
Exact solutions of a particle in a box with a delta function potential: The factorization method
We use the factorization method to find the exact eigenvalues and
eigenfunctions for a particle in a box with the delta function potential
. We show that the presence of the potential
results in the discontinuity of the corresponding ladder operators. The
presence of the delta function potential allows us to obtain the full spectrum
in the first step of the factorization procedure even in the weak coupling
limit .Comment: 8 pages, 2 figures, to appear in American Journal of Physic
Prediction and measurement of radiation damage to CMOS devices on board spacecraft
The CMOS Radiation Effects Measurement (CREM) experiment is presently being flown on the Explorer-55. The purpose of the experiment is to evaluate device performance in the actual space radiation environment and to correlate the respective measurements to on-the-ground laboratory irradiation results. The experiment contains an assembly of C-MOS and P-MOS devices shielded in front by flat slabs of aluminum and by a practically infinite shield in the back. Predictions of radiation damage to C-MOS devices are based on standard environment models and computational techniques. A comparison of the shifts in CMOS threshold potentials, that is, those measured in space to those obtained from the on-the-ground simulation experiment with Co-60, indicates that the measured space damage is smaller than predicted by about a factor of 2-3 for thin shields, but agrees well with predictions for thicker shields
Using the Uncharged Kerr Black Hole as a Gravitational Mirror
We extend the study of the possibility to use the Schwarzschild black hole as
a gravitational mirror to the more general case of an uncharged Kerr black
hole. We use the null geodesic equation in the equatorial plane to prove a
theorem concerning the conditions the impact parameter has to satisfy if there
shall exist boomerang photons. We derive an equation for these boomerang
photons and an equation for the emission angle. Finally, the radial null
geodesic equation is integrated numerically in order to illustrate boomerang
photons.Comment: 11 pages Latex, 3 Postscript figures, uufiles to compres
Gravitational coupling to two-particle bound states and momentum conservation in deep inelastic scattering
The momentum conservation sum rule for deep inelastic scattering (DIS) from
composite particles is investigated using the general theory of relativity. For
two 1+1 dimensional examples, it shown that covariant theories automatically
satisy the DIS momentum conservation sum rule provided the bound state is
covariantilly normalized. Therefore, in these cases the two DIS sum rules for
baryon conservation and momentum conservation are equivalent
Cosmological Relativity: A General-Relativistic Theory for the Accelerating Expanding Universe
Recent observations of distant supernovae imply, in defiance of expectations,
that the universe growth is accelerating, contrary to what has always been
assumed that the expansion is slowing down due to gravity. In this paper a
general-relativistic cosmological theory that gives a direct relationship
between distances and redshifts in an expanding universe is presented. The
theory is actually a generalization of Hubble's law taking gravity into account
by means of Einstein's theory of general relativity. The theory predicts that
the universe can have three phases of expansion, decelerating, constant and
accelerating, but it is shown that at present the first two cases are excluded,
although in the past it had experienced them. Our theory shows that the
universe now is definitely in the stage of accelerating expansion, confirming
the recent experimental results
About Gravitomagnetism
The gravitomagnetic field is the force exerted by a moving body on the basis
of the intriguing interplay between geometry and dynamics which is the analog
to the magnetic field of a moving charged body in electromagnetism. The
existence of such a field has been demonstrated based on special relativity
approach and also by special relativity plus the gravitational time dilation
for two different cases, a moving infinite line and a uniformly moving point
mass, respectively. We treat these two approaches when the applied cases are
switched while appropriate key points are employed. Thus, we demonstrate that
the strength of the resulted gravitomagnetic field in the latter approach is
twice the former. Then, we also discuss the full linearized general relativity
and show that it should give the same strength for gravitomagnetic field as the
latter approach. Hence, through an exact analogy with the electrodynamic
equations, we present an argument in order to indicate the best definition
amongst those considered in this issue in the literature. Finally, we
investigate the gravitomagnetic effects and consequences of different
definitions on the geodesic equation including the second order approximation
terms.Comment: 16 pages, a few amendments have been performed and a new section has
been adde
What is the topology of a Schwarzschild black hole?
We investigate the topology of Schwarzschild's black hole through the
immersion of this space-time in spaces of higher dimension. Through the
immersions of Kasner and Fronsdal we calculate the extension of the
Schwarzschild's black hole.Comment: 7 pages. arXiv admin note: substantial text overlap with
arXiv:1102.446
A Note on the Relativistic Covariance of the Cyclic Relations
It is shown that the Evans-Vigier modified electrodynamics is compatible with
the Relativity Theory.Comment: ReVTeX file, 14pp., no figure
- …