219 research outputs found
On Static Charged Black Holes in Type IIA on a Nearly-Kahler Coset
We study static, spherically symmetric black hole solutions in
four-dimensional N=2 gauged supergravity with one vector multiplet and one
hyper-tensor multiplet. This is derived from massive type IIA theory
compactified on the nearly-Kahler coset space G2/SU(3). It is well-known that
the Romans' mass parameter yields the Stuckelberg-type deformation of the gauge
field strengths in the four-dimensional system. This deformation requires that
all the (covariant) derivatives of the scalar fields must vanish and the
two-form field is closed. It turns out that charged solutions are forbidden.
This implies that only AdS vacua or Schwarzschild-AdS black holes are allowed
as the static, spherically symmetric solutions.Comment: 13 page
Defect (p,q) Five-branes
We study a local description of composite five-branes of codimension two. The
formulation is constructed by virtue of monodromy associated with two-torus. Applying conjugate monodromy
transformations to the complex structures of the two-torus, we obtain a field
configuration of a defect five-brane. This is a composite state of
defect NS5-branes and exotic -branes. We also obtain a new example
of hyper-K\"{a}hler geometry. This is an ALG space, a generalization of an ALF
space which asymptotically has a tri-holomorphic two-torus action. This
geometry appears in the conjugate configuration of a single defect KK5-brane.Comment: 22 pages, version published in Nuclear Physics
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