8 research outputs found
Gauged motion in general relativity and in Kaluza-Klein theories
In a recent paper [1] a new generalization of the Killing motion, the {\it
gauged motion}, has been introduced for stationary spacetimes where it was
shown that the physical symmetries of such spacetimes are well described
through this new symmetry. In this article after a more detailed study in the
stationary case we present the definition of gauged motion for general
spacetimes. The definition is based on the gauged Lie derivative induced by a
threading family of observers and the relevant reparametrization invariance. We
also extend the gauged motion to the case of Kaluza-Klein theories.Comment: 42 pages, revised version, typos correction along with some minor
changes, Revtex forma
Structure of Spinning Particle Suggested by Gravity, Supergravity and Low Energy String Theory
The structure of spinning particle suggested by the rotating Kerr-Newman
(black hole) solution, super-Kerr-Newman solution and the Kerr-Sen solution to
low energy string theory is considered. Main peculiarities of the Kerr spinning
particle are discussed: a vortex of twisting principal null congruence,
singular ring and the Kerr source representing a rotating relativistic disk of
the Compton size. A few stringy structures can be found in the real and complex
Kerr geometry.
Low-energy string theory predicts the existence of a heterotic string placed
on the sharp boundary of this disk. The obtained recently supergeneralization
of the Kerr-Newman solution suggests the existence of extra axial singular line
and fermionic traveling waves concentrating near these singularities.
We discuss briefly a possibility of experimental test of these predictions.Comment: Latex, 8 pages, talk at the International Workshop Spin'99, Prague,
5-11 September, 199
Complex Kerr Geometry and Nonstationary Kerr Solutions
In the frame of the Kerr-Schild approach, we consider the complex structure
of Kerr geometry which is determined by a complex world line of a complex
source. The real Kerr geometry is represented as a real slice of this complex
structure. The Kerr geometry is generalized to the nonstationary case when the
current geometry is determined by a retarded time and is defined by a
retarded-time construction via a given complex world line of source. A general
exact solution corresponding to arbitrary motion of a spinning source is
obtained. The acceleration of the source is accompanied by a lightlike
radiation along the principal null congruence. It generalizes to the rotating
case the known Kinnersley class of "photon rocket" solutions.Comment: v.3, revtex, 16 pages, one eps-figure, final version (to appear in
PRD), added the relation to twistors and algorithm of numerical computations,
English is correcte
On Mason's rigidity theorem
Following an argument proposed by Mason, we prove that there are no
algebraically special asymptotically simple vacuum space-times with a smooth,
shear-free, geodesic congruence of principal null directions extending
transversally to a cross-section of Scri. Our analysis leaves the door open for
escaping this conclusion if the congruence is not smooth, or not transverse to
Scri. One of the elements of the proof is a new rigidity theorem for the
Trautman-Bondi mass.Comment: minor typos correcte