2,108 research outputs found
Radiation Information from 1958 δ2
The telemetered radiation information from the satellite 1958 δ2
(Sputnik III) has been analyzed for sixty-two separate passes recorded
in College, Alaska. The data indicate a dependence of radiation intensity
on altitude in the range 250-500 km. Both the high and low
energy components apparently contribute to the overall increase of
intensity with altitude, but the presence of a continuous afterglow
in the scintillating crystal prevented detailed interpretation of the
results.IGY Project No. 32.42
NSF Grant No. Y/32.42/268Ye
BRST quantization of matrix models with constraints and two-dimensional Yang-Mills theory on the cylinder
BRST quantization of the one-dimensional constrained matrix model which
describes two-dimensional Yang-Mills theory on the cylinder is performed.
Classical and quantum BRST generators and BRST-invariant hamiltonians are
constructed. Evolution operator is expressed in terms of BRST path integral.
Advantages of the BRST quantization over the reduced phase space approach
leading to the theory of free fermions are discussed.Comment: 8 page
Non-Perturbative One-Loop Effective Action for Electrodynamics in Curved Spacetime
In this paper we explicitly evaluate the one-loop effective action in four
dimensions for scalar and spinor fields under the influence of a strong,
covariantly constant, magnetic field in curved spacetime. In the framework of
zeta function regularization, we find the one-loop effective action to all
orders in the magnetic field up to linear terms in the Riemannian curvature. As
a particular case, we also obtain the one-loop effective action for massless
scalar and spinor fields. In this setting, we found that the vacuum energy of
charged spinors with small mass becomes very large due entirely by the
gravitational correction.Comment: LaTeX, 23 page
Fourier Transforms of Lorentz Invariant Functions
Fourier transforms of Lorentz invariant functions in Minkowski space, with
support on both the timelike and the spacelike domains are performed by means
of direct integration. The cases of 1+1 and 1+2 dimensions are worked out in
detail, and the results for 1+n dimensions are given.Comment: 15 pages, 1 figur
Conformal Symmetry of Supergravities in AdS spaces
We show that the background field method applied to supergravity in adS
space-time provides the path integral for the theory in the bulk with conformal
symmetry associated with the isometry of the adS space. This in turn allows to
establish the rigid conformal invariance of the generating functional for the
supergravity correlators on the boundary.Comment: 14 pages, Late
Graded Majorana spinors
In many mathematical and physical contexts spinors are treated as Grassmann
odd valued fields. We show that it is possible to extend the classification of
reality conditions on such spinors by a new type of Majorana condition. In
order to define this graded Majorana condition we make use of
pseudo-conjugation, a rather unfamiliar extension of complex conjugation to
supernumbers. Like the symplectic Majorana condition, the graded Majorana
condition may be imposed, for example, in spacetimes in which the standard
Majorana condition is inconsistent. However, in contrast to the symplectic
condition, which requires duplicating the number of spinor fields, the graded
condition can be imposed on a single Dirac spinor. We illustrate how graded
Majorana spinors can be applied to supersymmetry by constructing a globally
supersymmetric field theory in three-dimensional Euclidean space, an example of
a spacetime where standard Majorana spinors do not exist.Comment: 16 pages, version to appear in J. Phys. A; AFK previously published
under the name A. F. Schunc
The Fermion Self-Energy during Inflation
We compute the one loop fermion self-energy for massless Dirac + Einstein in
the presence of a locally de Sitter background. We employ dimensional
regularization and obtain a fully renormalized result by absorbing all
divergences with BPHZ counterterms. An interesting technical aspect of this
computation is the need for a noninvariant counterterm owing to the breaking of
de Sitter invariance by our gauge condition. Our result can be used in the
quantum-corrected Dirac equation to search for inflation-enhanced quantum
effects from gravitons, analogous to those which have been found for massless,
minimally coupled scalars.Comment: 63 pages, 3 figures (uses axodraw.sty), LaTeX 2epsilon. Revised
version (to appear in Classical and Quantum Gravity) corrects some typoes and
contains some new reference
Bohmian trajectories and the Path Integral Paradigm. Complexified Lagrangian Mechanics
David Bohm shown that the Schr{\"o}dinger equation, that is a "visiting card"
of quantum mechanics, can be decomposed onto two equations for real functions -
action and probability density. The first equation is the Hamilton-Jacobi (HJ)
equation, a "visiting card" of classical mechanics, to be modified by the
Bohmian quantum potential. And the second is the continuity equation. The
latter can be transformed to the entropy balance equation. The Bohmian quantum
potential is transformed to two Bohmian quantum correctors. The first corrector
modifies kinetic energy term of the HJ equation, and the second one modifies
potential energy term. Unification of the quantum HJ equation and the entropy
balance equation gives complexified HJ equation containing complex kinetic and
potential terms. Imaginary parts of these terms have order of smallness about
the Planck constant. The Bohmian quantum corrector is indispensable term
modifying the Feynman's path integral by expanding coordinates and momenta to
imaginary sector.Comment: 14 pages, 3 figures, 46 references, 48 equation
Representations of Spacetime Alternatives and Their Classical Limits
Different quantum mechanical operators can correspond to the same classical
quantity. Hermitian operators differing only by operator ordering of the
canonical coordinates and momenta at one moment of time are the most familiar
example. Classical spacetime alternatives that extend over time can also be
represented by different quantum operators. For example, operators representing
a particular value of the time average of a dynamical variable can be
constructed in two ways: First, as the projection onto the value of the time
averaged Heisenberg picture operator for the dynamical variable. Second, as the
class operator defined by a sum over those histories of the dynamical variable
that have the specified time-averaged value. We show both by explicit example
and general argument that the predictions of these different representations
agree in the classical limit and that sets of histories represented by them
decohere in that limit.Comment: 11 pages, 10 figures, Revtex4, minor correction
Background, current status, and prognosis of the ongoing slush hydrogen technology development program for the NASP
Among the Hydrogen Projects at the NASA Lewis Research Center (NASA LeRC), is the task of implementing and managing the Slush Hydrogen (SLH2) Technology Program for the United States' National AeroSpace Plane Joint Program Office (NASP JPO). The objectives of this NASA LeRC program are to provide verified numerical models of fluid production, storage, transfer, and feed systems and to provide verified design criteria for other engineered aspects of SLH2 systems germane to a NASP. The pursuit of these objectives is multidimensional, covers a range of problem areas, works these to different levels of depth, and takes advantage of the resources available in private industry, academia, and the U.S. Government. A summary of the NASA LeRC overall SLH2 program plan, is presented along with its implementation, the present level of effort in each of the program areas, some of the results already in hand, and the prognosis for the effort in the immediate future
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