7,049 research outputs found
Discrete Symmetries of Off-Shell Electromagnetism
We discuss the discrete symmetries of the Stueckelberg-Schrodinger
relativistic quantum theory and its associated 5D local gauge theory, a
dynamical description of particle/antiparticle interactions, with monotonically
increasing Poincare-invariant parameter. In this framework, worldlines are
traced out through the parameterized evolution of spacetime events, advancing
or retreating with respect to the laboratory clock, with negative energy
trajectories appearing as antiparticles when the observer describes the
evolution using the laboratory clock. The associated gauge theory describes
local interactions between events (correlated by the invariant parameter)
mediated by five off-shell gauge fields. These gauge fields are shown to
transform tensorially under under space and time reflections, unlike the
standard Maxwell fields, and the interacting quantum theory therefore remains
manifestly Lorentz covariant. Charge conjugation symmetry in the quantum theory
is achieved by simultaneous reflection of the sense of evolution and the fifth
scalar field. Applying this procedure to the classical gauge theory leads to a
purely classical manifestation of charge conjugation, placing the CPT
symmetries on the same footing in the classical and quantum domains. In the
resulting picture, interactions do not distinguish between particle and
antiparticle trajectories -- charge conjugation merely describes the
interpretation of observed negative energy trajectories according to the
laboratory clock.Comment: 26 page
Satellite remote sensing for ice sheet research
Potential research applications of satellite data over the terrestrial ice sheets of Greenland and Antarctica are assessed and actions required to ensure acquisition of relevant data and appropriate processing to a form suitable for research purposes are recommended. Relevant data include high-resolution visible and SAR imagery, infrared, passive-microwave and scatterometer measurements, and surface topography information from laser and radar altimeters
Occam's razor meets WMAP
Using a variety of quantitative implementations of Occam's razor we examine
the low quadrupole, the ``axis of evil'' effect and other detections recently
made appealing to the excellent WMAP data. We find that some razors {\it fully}
demolish the much lauded claims for departures from scale-invariance. They all
reduce to pathetic levels the evidence for a low quadrupole (or any other low
cut-off), both in the first and third year WMAP releases. The ``axis of
evil'' effect is the only anomaly examined here that survives the humiliations
of Occam's razor, and even then in the category of ``strong'' rather than
``decisive'' evidence. Statistical considerations aside, differences between
the various renditions of the datasets remain worrying
Duality in Off-Shell Electromagnetism
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.Comment: 18 page
Task 7 space storable propellant module environmental control technology
Design of thermal control system for cryogenic fluid storage tank
Task 3 space storable propellant module environmental control technology Summary report
Thermal control system for space storable propellant modul
Space storable propellant module thermal control technology. Volume 2 - F2/N2H4 propulsion module Summary report
Space storable fluorine/hydrazine tank module thermal control design for Jupiter missio
Probability Density of the Multipole Vectors for a Gaussian Cosmic Microwave Background
We review Maxwell's multipole vectors, and elucidate some of their
mathematical properties, with emphasis on the application of this tool to the
cosmic microwave background (CMB). In particular, for a completely random
function on the sphere (corresponding to the statistically isotropic Gaussian
model of the CMB), we derive the full probability density function of the
multipole vectors. This function is used to analyze the internal configurations
of the third-year Wilkinson Microwave Anisotropy Probe quadrupole and octopole,
and we show the observations are consistent with the Gaussian prediction. A
particular aspect is the planarity of the octopole, which we find not to be
anomalous.Comment: 12 pages, 7 figures, MNRAS styl
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