2 research outputs found
On Horizons and Plane Waves
We investigate the possibility of having an event horizon within several
classes of metrics that asymptote to the maximally supersymmetric IIB plane
wave. We show that the presence of a null Killing vector (not necessarily
covariantly constant) implies an effective separation of the Einstein equations
into a standard and a wave component. This feature may be used to generate new
supergravity solutions asymptotic to the maximally supersymmetric IIB plane
wave, starting from standard seed solutions such as branes or intersecting
branes in flat space. We find that in many cases it is possible to preserve the
extremal horizon of the seed solution. On the other hand, non-extremal
deformations of the plane wave solution result in naked singularities. More
generally, we prove a no-go theorem against the existence of horizons for
backgrounds with a null Killing vector and which contain at most null matter
fields. Further attempts at turning on a nonzero Hawking temperature by
introducing additional matter have proven unsuccessful. This suggests that one
must remove the null Killing vector in order to obtain a horizon. We provide a
perturbative argument indicating that this is in fact possible.Comment: 46 pp, 1 figur
The Kerr-Newman-Godel Black Hole
By applying a set of Hassan-Sen transformations and string dualities to the
Kerr-Godel solution of minimal D=5 supergravity we derive a four parameter
family of five dimensional solutions in type II string theory. They describe
rotating, charged black holes in a rotating background. For zero background
rotation, the solution is D=5 Kerr-Newman; for zero charge it is Kerr-Godel. In
a particular extremal limit the solution describes an asymptotically Godel BMPV
black hole.Comment: 12 pages, LaTeX, no figures; v2: one reference added, very minor
changes; to appear in CQ