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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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For a stochastic stress-energy tensor associated with cosmic turbulence, it is observed that Einstein's equations imply fluctuations in the space-time metric tensor. Such metrical fluctuations are shown to engender modified values for the average effective proper density and total pressure and thus to alter the solutions to the Friedman equations.
Homogeneous solution of Einstein-Maxwell equations assuming invariant space-time metric and electromagnetic field
Models of spherically symmetric nonstatic processes, including relativistic collapse to Schwarzschild sphere, constructed by space-time metrics
The relativity experiment on Helios (Experiment 11) uses S-band and Doppler data, and spacecraft-solar-orbital data to measure the effects of general relativity in the solar system and the quadrupole moment in the solar gravitational field. Specifically, Experiment 11 is converned with measuring the following effects: (1) relativistic orbital corrections described by two parameters of the space-time metric which are both equal to unity in Einstein's theory; (2) orbital perturbations caused by a finite quadrupole moment of an oblate sun, described by zonal harmonics in the solar gravitational field.
A propulsion concept was developed based on a proposed resonance between coherent, pulsed electromagnetic wave forms, and gravitational wave forms (or space-time metrics). Using this concept a spacecraft propulsion system potentially capable of galactic and intergalactic travel without prohibitive travel times was designed. The propulsion system utilizes recent research associated with magnetic field line merging, hydromagnetic wave effects, free-electron lasers, laser generation of megagauss fields, and special structural and containment metals. The research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described.
Cosmic matter-antimatter asymmetry due to the gravitational interaction alone is discussed, considering the gravitational coupling of fermion matter related to the Yang-Mills (1954) gauge symmetry with the unique generalization of the four-dimensional Poincare group. Attention is given to the case of weak static fields which determines the space-time metric where only large source terms are retained. In addition, considering lowest-order Feynman diagrams, there are presented gravitational potential energies between fermions, between antifermions, and between a fermion and an antifermion. It is concluded that the gravitational force between matter is different from that between antimatter; implications from this concerning the evolution of the universe are discussed.
Relationship of Riemannian space-times with metric tensors in solution of vacuum field equations
Space-time Riemann metric for scalar-tensor gravitational theories with arbitrary omega parameter
Solution of Einstein field equations with incoherent matter for homogeneous space-time case using spinor technique, including Goedel theorem proof
Euclidean nature of relativistic rotating disk in conclusions of Eddington and Lorentz
Retarded observer time as coordinate in relativistic spherical hydrodynamic equations prevents Schwarzschild surface formation
General relativistic dyadic formalism applied to metrics of rigid bodies moving in Einstein space of uniform space-time curvature
Elliptic Kruskal-Schwarzschild space, discussing identification of points which limit Kruskal space into Minkowski space
Kruskal space in general relativity and uniform accelerated rigid rod in special relativity show striking formal similarities
Static axisymmetric interior solution of Einstein field equations which matches smoothly to one of Weyl exterior solutions
Parametrization of reduced problem of stationary axially symmetric gravity fields
The entire field of astronomy is in very rapid flux, and at the center of interest are problems relating to the very dense, rotating, neutron stars observed as pulsars. the hypothesized collapsed remains of stars known as black holes, and quasars. Degenerate metric form, or Kerr-Schild metric form, was used to study several problems related to intense gravitational fields.
Pairs of Relativistic Space-Times are classified according to their Segre characteristics. Suitable bases consisting of pseudo-orthonormal tetrads are constructed and the condition that the spaces should have corresponding geodesics is imposed. contain spaces with corresponding geodesics. It is found that the [3, 1] and [(3, 1)] classes contain spaces with corresponding geodesics. Of these metrics, the vacuum ones are shown to be algebraically special, in the sense of the Petrov classification.