The space-time metric inside a rotating cylinder

Author(s):  
H. Davies ◽  
T. A. Caplan

AbstractIt is shown that the space-time region inside an axially symmetric, infinite, rotating, cylindrical mass distribution is necessarily Minkowskian.

2009 ◽  
Vol 24 (18n19) ◽  
pp. 3571-3576 ◽  
Author(s):  
SUPRIYA KAR

Inspired by the space-time noncommutativity on a D5-brane world, in a type IIB string theory, we explore the possibility of an emergent 4D ordinary space-time in the formalism. In particular, a curved D3-brane dynamics is worked out to obtain an axially symmetric and a spherically symmetric AdS and dS black holes. Extremal geometries are analyzed, using the noncommutative scaling. The emerging two dimensional semi-classical black holes are investigated to yield evidence for extra dimensions in the curved brane-world. Interestingly, a tunneling between dS to AdS vacua in the formalism is briefly discussed by incorporating the Hagedorn transitions in string theory.


2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Debojit Sarma ◽  
Faizuddin Ahmed ◽  
Mahadev Patgiri

We present an axially symmetric, asymptotically flat empty space solution of the Einstein field equations containing a naked singularity. The space-time is regular everywhere except on the symmetry axis where it possesses a true curvature singularity. The space-time is of type D in the Petrov classification scheme and is locally isometric to the metrics of case IV in the Kinnersley classification of type D vacuum metrics. Additionally, the space-time also shows the evolution of closed timelike curves (CTCs) from an initial hypersurface free from CTCs.


2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Faizuddin Ahmed

We present a gravitational collapse null dust solution of the Einstein field equations. The space-time is regular everywhere except on the symmetry axis where it possesses a naked curvature singularity and admits one parameter isometry group, a generator of axial symmetry along the cylinder which has closed orbits. The space-time admits closed timelike curves (CTCs) which develop at some particular moment in a causally well-behaved manner and may represent a Cosmic Time Machine. The radial geodesics near the singularity and the gravitational lensing (GL) will be discussed. The physical interpretation of this solution, based on the study of the equation of the geodesic deviation, will be presented. It was demonstrated that this solution depends on the local gravitational field consisting of two components with amplitudes Ψ2 and Ψ4.


2014 ◽  
Vol 22 (S1) ◽  
pp. S145-S162
Author(s):  
Alexander Reutlinger

Several philosophers of biology have argued for the claim that the generalizations of biology are historical and contingent.1–5 This claim divides into the following sub-claims, each of which I will contest: first, biological generalizations are restricted to a particular space-time region. I argue that biological generalizations are universal with respect to space and time. Secondly, biological generalizations are restricted to specific kinds of entities, i.e. these generalizations do not quantify over an unrestricted domain. I will challenge this second claim by providing an interpretation of biological generalizations that do quantify over an unrestricted domain of objects. Thirdly, biological generalizations are contingent in the sense that their truth depends on special (physically contingent) initial and background conditions. I will argue that the contingent character of biological generalizations does not diminish their explanatory power nor is it the case that this sort of contingency is exclusively characteristic of biological generalizations.


1991 ◽  
Vol 06 (24) ◽  
pp. 2189-2195
Author(s):  
AMIR LEVINSON ◽  
AHARON DAVIDSON

Stationary, axially symmetric solutions of Einstein equations in a free 5-dimensional Kaluza–Klein space-time are derived. The electric charge and magnetic moment are generated by a fictitious boost involving the extra dimension. The associated gyromagnetic factor tends to unity at the ultra-relativistic limit. The solution derived interpolates between the Kerr and the Belinsky–Ruffini solutions.


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