Effect of NUT parameter on the analytic extension of the Cauchy horizon that develop in colliding wave spacetimes

The Cauchy horizon forming colliding wave solution due to Chandrasekhar and Xanthopoulos (CX) has been generalized by inclusion of the NUT (Newman - Unti - Tamburino) parameter. This is done by transforming the part of the inner horizon region of a Kerr-Newman-NUT black hole into the space of colliding waves. By taking appropriate combination of Killing vectors and analytically extending beyond the Cauchy horizon the time-like hyperbolic sigularities are resolved as well. This provides another example of its kind among the type - D metrics with special emphasis on the role of the NUT parameter. Finally, it is shown that horizons of colliding higher dimensional plane waves obtained from the black p-branes undergoes a similar procedure of analytic extension.Comment: 26 pages. 3 ps figure

A new Einstein-nonlinear electrodynamics solution in 2+1-dimensions

We introduce a class of solutions in $2+1-$dimensional Einstein-Power-Maxwell theory for circularly symmetric electric field. The electromagnetic field is considered with an angular component given by % F_{\mu \nu }=E_{0}\delta_{\mu }^{t}\delta_{\nu }^{\theta } for $E_{0}=$ constant. First, we show that the metric for zero cosmological constant and the Power-Maxwell Lagrangian of the form of $\sqrt{\left\vert F_{\mu \nu }F^{\mu \nu }\right\vert }$, coincides with the solution given in $2+1-$% dimensional gravity coupled with a massless, self interacting real scalar field. With the same Lagrangian and a non-zero cosmological constant we obtain a non-asymptotically flat wormhole solution in $2+1-$dimensions. The confining motions of massive charged and chargeless particles are investigated too. Secondly, another interesting solution is given for zero cosmological constant together with conformal invariant condition. The formation of timelike naked singularity for this particular case is investigated within the framework of the quantum mechanics. Quantum fields obeying the Klein-Gordon and Dirac equations are used to probe the singularity and test the quantum mechanical status of the singularity.Comment: 9 pages one figure. With major revision and singularity analysis is adde

Probing naked singularities in the charged and uncharged γ\gamma-metrics with quantum wave packets

The non-trivial naked singularities that possess directional behavior in the charged and uncharged Zipoy-Voorhees (ZV) spacetimes, known as {\gamma} - metrics are investigated within the context of quantum mechanics. Classically singular spacetime is understood as a geodesic incompleteness with respect to a particle probe, while quantum singularity is understood as a non-unique evolution of test quantum wave packets. In this study, quantum wave packets obeying Klein - Gordon equation are used to probe timelike naked singularities. It is shown by rigorous mathematical calculations that the outermost singularity developed in the charged and uncharged Zipoy-Voorhees spacetime on the equatorial plane is quantum mechanically singular for all values of the deformation parameter {\gamma}. However, directional singularities that develop on the symmetry axis is shown to be healed partially for specific range of the parameter {\gamma}, if the analysis is restricted purposely to only specific mode (s-wave mode). Allowing arbitrary modes, classical directional singularities remains quantum singular.Comment: Slightly detailed versio

Neutrino Fields in a Sandwich Gravitational Wave Background

Sandwich gravitational waves are given globally in terms of step functions at the boundaries. Linearized Einstein-Weyl equations are solved exactly in this background in Rosen coordinates. Depending on the geometry and composition of the sandwich wave, the neutrino's energy-momentum redistributes itself. At the test field level, since the background will not change, the neutrino's energy density in particular will show variations between positive and negative extrema when crossing the sandwich wave. This may reveal facts about the weakly interacting neutrinos in cosmology.Comment: Accepted Version to appear in Class.Quant.Gra

Restricted Class of Colliding Einstein-Yang-Mills Plane Waves

By gauging an Abelian electromagnetic (em) solution through a non-Abelian transformation and in accordance with a theorem proved long time ago, we construct a simple class of colliding Einstein-Yang-Mills (EYM) plane waves. The solution is isometric to the Wu-Yang charged Kerr-Newman (KN) black hole and shares much of the properties satisfied by colliding Einstein-Maxwell (EM) plane waves. In the linear polarization limit with unit degenerate charge it reduces to the Bell-Szekeres (BS) solution for colliding em shock waves.Comment: 9 pages, no figures, To appear in IJMP

Colliding Wave Solutions in a Symmetric Non-metric Theory

A method is given to generate the non-linear interaction (collision) of linearly polarized gravity coupled torsion waves in a non-metric theory. Explicit examples are given in which strong mutual focussing of gravitational waves containing impulsive and shock components coupled with torsion waves does not result in a curvature singularity. However, the collision of purely torsion waves displays a curvature singularity in the region of interaction.Comment: 16 pages, 1 ps figure, It will appear in Int. Jour. of Theor. Physic