2,108 research outputs found

    Radiation Information from 1958 δ2

    Get PDF
    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

    Get PDF
    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 NN free fermions are discussed.Comment: 8 page

    Non-Perturbative One-Loop Effective Action for Electrodynamics in Curved Spacetime

    Full text link
    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

    Full text link
    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

    Get PDF
    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

    Full text link
    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

    Full text link
    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

    Full text link
    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

    Full text link
    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

    Get PDF
    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
    • …
    corecore