Penrose's quasi-local mass and cylindrically symmetric spacetimes

1990 ◽  
Vol 7 (12) ◽  
pp. 2237-2266 ◽  
Author(s):  
K P Tod
Keyword(s):  
Local Mass ◽  
Cylindrically Symmetric ◽  
Symmetric Spacetimes ◽  
Cylindrically Symmetric Spacetimes

scholarly journals DIRAC ANALYSIS AND INTEGRABILITY OF GEODESIC EQUATIONS FOR CYLINDRICALLY SYMMETRIC SPACETIMES

2003 ◽  
Vol 12 (08) ◽  
pp. 1431-1444 ◽  
Author(s):  
UGUR CAMCI
Keyword(s):  
Symplectic Structure ◽  
Equations Of Motion ◽  
First Order ◽  
Geodesic Equations ◽  
Cylindrically Symmetric ◽  
Symmetric Spacetimes ◽  
Constraint Analysis ◽  
Stationary Spacetime ◽  
Cylindrically Symmetric Spacetimes ◽  
Geodesic Equations Of Motion

Dirac's constraint analysis and the symplectic structure of geodesic equations are obtained for the general cylindrically symmetric stationary spacetime. For this metric, using the obtained first order Lagrangian, the geodesic equations of motion are integrated, and found some solutions for Lewis, Levi-Civita, and Van Stockum spacetimes.

scholarly journals Cylindrical wormholes: A search for viable phantom-free models in GR

2019 ◽  
Vol 28 (13) ◽  
pp. 1941008 ◽  
Author(s):  
K. A. Bronnikov ◽  
S. V. Bolokhov ◽  
M. V. Skvortsova
Keyword(s):  
Energy Condition ◽  
Special Kind ◽  
Scalar Fields ◽  
Exotic Matter ◽  
Anisotropic Fluid ◽  
Internal Source ◽  
Cylindrically Symmetric ◽  
Symmetric Spacetimes ◽  
Asymptotic Flatness ◽  
Anisotropic Fluids

The well-known problem of wormholes in General Relativity (GR) is the necessity of exotic matter, violating the Weak Energy Condition (WEC), for their support. This problem looks easier if, instead of island-like configurations, one considers string-like ones, among them, cylindrically symmetric spacetimes with rotation. However, for cylindrical wormhole solutions, a problem is the lacking asymptotic flatness, making it impossible to observe their entrances as local objects in our universe. It was suggested to solve this problem by joining a wormhole solution to flat asymptotic regions at some surfaces [Formula: see text] and [Formula: see text] on different sides of the throat. The configuration then consists of three regions, the internal one containing a throat and two flat external ones. We discuss different kinds of source matter suitable for describing the internal regions of such models (scalar fields, isotropic and anisotropic fluids) and present two examples where the internal matter itself and the surface matter on both junction surfaces [Formula: see text] respect the WEC. In one of these models, the internal source is a stiff perfect fluid whose pressure is equal to its energy density, in the other, it is a special kind of anisotropic fluid. Both models are free from closed timelike curves. We thus obtain examples of regular twice asymptotically flat wormhole models in GR without exotic matter and without causality violations.

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