Conditions for nonexistence of static or stationary, Einstein-Maxwell, non-inheriting black-holes

We consider asymptotically-flat, static and stationary solutions of the Einstein equations representing Einstein-Maxwell space-times in which the Maxwell field is not constant along the Killing vector defining stationarity, so that the symmetry of the space-time is not inherited by the electromagnetic field. We find that static degenerate black hole solutions are not possible and, subject to stronger assumptions, nor are static, non-degenerate or stationary black holes. We describe the possibilities if the stronger assumptions are relaxed.Comment: 19 pages, to appear in GER

Zur Klassifizierung mehrparametriger Dämpfungsmodelle

Vier Dämpfungsmodelle wurden in Nolte und Müller zum Hagen (2005) hinsichtlich ihrer mathematischen Struktur beschriebenen: Das Maxwell-Modell, das Jeffreys-Modell, das Kelvin-Voigt-Modell sowie das Poynting-Thomson-Modell. Die Diskussion der Modelle erfolgte an den partiellen Differentialgleichungen in der Verschiebung. Weitere physikalische Untersuchungen fanden statt. Es hat sich, dass zwei der partiellen Differentialgleichungen (Dämpfungsmodell nach Maxwell und Poynting-Thomson) rein hyperbolisch sind und die zwei anderen partiellen Differentialgleichungen vom parabolischen-hyperbolischen Typ sind. Diese Erkenntnis wird in dieser Arbeit auf mehrparametrige Dämpfungsmodelle übertragen

Einstein equations in the null quasi-spherical gauge III: numerical algorithms

We describe numerical techniques used in the construction of our 4th order evolution for the full Einstein equations, and assess the accuracy of representative solutions. The code is based on a null gauge with a quasi-spherical radial coordinate, and simulates the interaction of a single black hole with gravitational radiation. Techniques used include spherical harmonic representations, convolution spline interpolation and filtering, and an RK4 "method of lines" evolution. For sample initial data of "intermediate" size (gravitational field with 19% of the black hole mass), the code is accurate to 1 part in 10^5, until null time z=55 when the coordinate condition breaks down.Comment: Latex, 38 pages, 29 figures (360Kb compressed

On the existence of Killing vector fields

In covariant metric theories of coupled gravity-matter systems the necessary and sufficient conditions ensuring the existence of a Killing vector field are investigated. It is shown that the symmetries of initial data sets are preserved by the evolution of hyperbolic systems.Comment: 9 pages, no figure, to appear in Class. Quant. Gra

Static self-gravitating many-body systems in Einstein gravity

We consider the problem of constructing static, elastic, many-body systems in Einstein gravity. The solutions constructed are deformations of static many-body configurations in Newtonian gravity. No symmetry assumptions are made.Comment: 15 page

Quantization of Gauge Field Theories on the Front-Form without Gauge Constraints I : The Abelian Case

Recently, we have proposed a new front-form quantization which treated both the $x^{+}$ and the $x^{-}$ coordinates as front-form 'times.' This quantization was found to preserve parity explicitly. In this paper we extend this construction to local Abelian gauge fields . We quantize this theory using a method proposed originally by Faddeev and Jackiw . We emphasize here the feature that quantizing along both $x^+$ and $x^-$ , gauge theories does not require extra constraints (also known as 'gauge conditions') to determine the solution uniquely.Comment: 18 pages, phyzz

Symmetries of spacetime and their relation to initial value problems

We consider covariant metric theories of coupled gravity-matter systems satisfying the following two conditions: First, it is assumed that, by a hyperbolic reduction process, a system of first order symmetric hyperbolic partial differential equations can be deduced from the matter field equations. Second, gravity is supposed to be coupled to the matter fields by requiring that the Ricci tensor is a smooth function of the basic matter field variables and the metric. It is shown then that the ``time'' evolution of these type of gravity-matter systems preserves the symmetries of initial data specifications.Comment: 12 pages, to appear in Class. Quant. Gra

Ghost points in inverse scattering constructions of stationary Einstein metrics

We prove a removable singularities theorem for stationary Einstein equations, with useful implications for constructions of stationary solutions using soliton methods

Uniqueness Theorem for Generalized Maxwell Electric and Magnetic Black Holes in Higher Dimensions

Based on the conformal energy theorem we prove the uniqueness theorem for static higher dimensional electrically and magnetically charged black holes being the solution of Einstein (n-2)-gauge forms equations of motion. Black hole spacetime contains an asymptotically flat spacelike hypersurface with compact interior and non-degenerate components of the event horizon.Comment: 7 pages, RevTex, to be published in Phys.Rev.D1

Uniqueness Theorem for Static Black Hole Solutions of sigma-models in Higher Dimensions

We prove the uniqueness theorem for self-gravitating non-linear sigma-models in higher dimensional spacetime. Applying the positive mass theorem we show that Schwarzschild-Tagherlini spacetime is the only maximally extended, static asymptotically flat solution with non-rotating regular event horizon with a constant mapping.Comment: 5 peges, Revtex, to be published in Class.Quantum Gra