A GENERALIZED METRIC OF GRAVITATION

1992 ◽  
Vol 07 (13) ◽  
pp. 3133-3139 ◽  
Author(s):  
ALI EL-TAHIR
Keyword(s):  
Scalar Curvature ◽  
Weak Field ◽  
Space Time ◽  
Isotropic Space ◽  
Generalized Metric

Useful expressions relating the metric components grr and gtt of the static isotropic space–time, and the scalar curvature R, with the general Lagrangian are obtained. A generalized metric of gravity is introduced, which is essentially nonsingular, and reducible to cosmological and hence Schwarzschild geometries by imposing a weak-field constraint.

scholarly journals THE LOW ENERGY EFFECTIVE LAGRANGIAN FOR PHOTON INTERACTIONS IN ANY DIMENSION

1996 ◽  
Vol 11 (02) ◽  
pp. 253-269 ◽  
Author(s):  
A. RITZ ◽  
R. DELBOURGO
Keyword(s):  
Dimensional Space ◽  
Effective Interaction ◽  
Bernoulli Polynomial ◽  
Weak Field ◽  
Space Time ◽  
Low Energy ◽  
Time Dimension ◽  
Effective Lagrangian ◽  
Dimensional Space Time ◽  
Photon Interactions

The subject of low energy photon-photon scattering is considered in arbitrary-dimensional space-time and the interaction is widened to include scattering events involving an arbitrary number of photons. The effective interaction Lagrangian for these processes in QED has been determined in a manifestly invariant form. This generalization resolves the structure of the weak field Euler-Heisenberg Lagrangian and indicates that the component invariant functions have coefficients related not only to the space-time dimension but also to the coefficients of the Bernoulli polynomial.

scholarly journals Gravitation in Theory of Space-Time Film and Galactic Soliton

2021 ◽  
Vol 2081 (1) ◽  
pp. 012016
Author(s):  
Alexander A Chernitskii
Keyword(s):  
Dark Matter ◽  
Scalar Field ◽  
Spiral Structure ◽  
Gravitational Interaction ◽  
Film Theory ◽  
Weak Field ◽  
Space Time ◽  
Gravitational Attraction ◽  
Model Formulation ◽  
Fundamental Field

Abstract The scalar field of extremal space-time film is considered as unified fundamental field. Metrical interaction between solitons-particles as gravitational interaction is considered here in approximation of a weak fundamental field. It is shown that the signature of metrics {-,+,+,+} in the model formulation provides the observable gravitational attraction to a region with bigger energy density of the fundamental field. The induced gravitational interaction in the space-time film theory is applied to stars in a galaxy. The conception of galaxy soliton of space-time film is introduced. A weak field asymptotic solution for a galaxy soliton is proposed. It is shown that the effective metrics for this solution can provide the observable velocity curves for galaxies and explains their spiral structure. Thus a solution for so-called dark matter problem in the framework of space-time film theory is proposed.

VORTICES IN CURVED SPACE-TIME

1993 ◽  
Vol 08 (38) ◽  
pp. 3665-3672 ◽  
Author(s):  
J.D. EDELSTEIN ◽  
G. LOZANO ◽  
F.A. SCHAPOSNIK
Keyword(s):  
Scalar Curvature ◽  
Gauge Field ◽  
Space Time ◽  
Higgs Model ◽  
Curved Space ◽  
Abelian Higgs Model ◽  
Vortex Solutions ◽  
Chern Simons ◽  
Higgs Scalar

We study an Abelian Higgs model coupled to a background metric. We find Bogomol’nyi equations when the coupling is achieved through an Rɸ2 term (R being the scalar curvature and ɸ the Higgs scalar). Remarkably, these equations coincide with those arising in models where the gauge field dynamics is governed by a Chern-Simons term so that vortex solutions in our system can be related to self-dual Chern-Simons vortices.

scholarly journals w = 1/3 to w = −1 evolution in a Robertson–Walker space-time with constant scalar curvature

2019 ◽  
Vol 16 (04) ◽  
pp. 1950061 ◽  
Author(s):  
Luca Guido Molinari ◽  
Carlo Alberto Mantica
Keyword(s):  
Scalar Curvature ◽  
Ricci Tensor ◽  
Constant Scalar Curvature ◽  
Flat Space ◽  
Space Time ◽  
Spatial Curvature ◽  
Limit Values ◽  
Pure Radiation ◽  
Age Of The Universe ◽  
The Universe

The Ricci tensor of a Robertson–Walker (RW) space-time is here specified by requiring constancy of the scalar curvature and a vanishing spatial curvature. By entering this Ricci tensor in Einstein’s equations (without cosmological constant), the cosmological fluid shows a transition from a pure radiation to a Lambda equation of state. In other words, the RW geometry with constant scalar curvature and flat space fixes the limit values [Formula: see text] and [Formula: see text], without any hypothesis on the cosmological fluid. The value of the scalar curvature fixes the time-scale for the transition. For this reason, we investigate the ‘toy-universe’ with Hubble parameter [Formula: see text] and temperature [Formula: see text][Formula: see text]K. The model predicts an age of the universe in the range 7.3–13.7[Formula: see text]Gyr.

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