34 research outputs found
Massless Black Holes as Black Diholes and Quadruholes
Massless black holes can be understood as bound states of a (positive mass)
extreme a=\sqrt{3} black hole and a singular object with opposite (i.e.
negative) mass with vanishing ADM (total) mass but non-vanishing gravitational
field. Supersymmetric balance of forces is crucial for the existence of this
kind of bound states and explains why the system does not move at the speed of
light. We also explain how supersymmetry allows for negative mass as long as it
is never isolated but in bound states of total non-negative mass.Comment: Version to be published in Physical Review Letters. Latex2e fil
Duality Versus Supersymmetry and Compactification
We study the interplay between T-duality, compactification and supersymmetry.
We prove that when the original configuration has unbroken space-time
supersymmetries, the dual configuration also does if a special condition is
met: the Killing spinors of the original configuration have to be independent
on the coordinate which corresponds to the isometry direction of the bosonic
fields used for duality. Examples of ``losers" (T-duals are not supersymmetric)
and ``winners" (T-duals are supersymmetric) are given.Comment: LaTeX file, 19 pages, U. of Groningen Report UG-8/94, Stanford U.
Report SU-ITP-94-19, QMW College Report QMW-PH-94-1
FERMION ZERO MODES AND BLACK-HOLE HYPERMULTIPLETS WITH RIGID SUPERSYMMETRY
The gravitini zero modes riding on top of the extreme Reissner-Nordstrom
black-hole solution of N=2 supergravity are shown to be normalizable. The
gravitini and dilatini zero modes of axion-dilaton extreme black-hole solutions
of N=4 supergravity are also given and found to have finite norms. These norms
are duality invariant. The finiteness and positivity of the norms in both cases
are found to be correlated with the Witten-Israel-Nester construction; however,
we have replaced the Witten condition by the pure-spin-3/2 constraint on the
gravitini. We compare our calculation of the norms with the calculations which
provide the moduli space metric for extreme black holes.
The action of the N=2 hypermultiplet with an off-shell central charge
describes the solitons of N=2 supergravity. This action, in the
Majumdar-Papapetrou multi-black-hole background, is shown to be N=2 rigidly
supersymmetric.Comment: 18 pages, LaTe
Supersymmetry and Stationary Solutions in Dilaton-Axion Gravity
New stationary solutions of -dimensional dilaton-axion gravity are
presented, which correspond to the charged Taub-NUT and Israel-Wilson-Perjes
(IWP) solutions of Einstein-Maxwell theory. The charged axion-dilaton Taub-NUT
solutions are shown to have a number of interesting properties: i) manifest
symmetry, ii) an infinite throat in an extremal limit, iii) the
throat limit coincides with an exact CFT construction.
The IWP solutions are shown to admit supersymmetric Killing spinors, when
embedded in supergravity. This poses a problem for the interpretation
of supersymmetric rotating solutions as physical ground states. In the context
of -dimensional geometry, we show that dimensionally lifted versions of the
IWP solutions are dual to certain gravitational waves in string theory.Comment: 23 pages (latex), SU-ITP-94-12, UMHEP-407, QMW-PH-94-1
Black-Hole-Wave Duality in String Theory
Extreme 4-dimensional dilaton black holes embedded into 10-dimensional
geometry are shown to be dual to the gravitational waves in string theory. The
corresponding gravitational waves are the generalization of pp-fronted waves,
called supersymmetric string waves. They are given by Brinkmann metric and the
two-form field, without a dilaton. The non-diagonal part of the metric of the
dual partner of the wave together with the two-form field correspond to the
vector field in 4-dimensional geometry of the charged extreme black holes.Comment: 12 pages, LaTeX, preprint UG-3/94, SU-ITP-94-11, QMW-PH-94-1
Exact SU(2)*U(1) Stringy Black Holes
Extreme magnetic dilaton black holes are promoted to exact solutions of
heterotic string theory with unbroken supersymmetry. With account taken of
alpha' corrections this is accomplished by supplementing the known solutions
with SU(2) Yang-Mills vectors and scalars in addition to the already existing
Abelian U(1) vector field. The solution has a simple analytic form and includes
multi-black-holes. The issue of exactness of other black-hole-type solutions,
including extreme dilaton electrically charged black holes and Taub-NUT
solutions is discussed.Comment: 10 pages, SU-ITP-94-27 and QMW-PH-94-34 (version accepted for
publication in Phys. Rev., contains a discussion of (4.1) supersymmetry of
the black hole sigma model
Duality Symmetric Quantization of Superstring
A general covariant quantization of superparticle, Green-Schwarz superstring
and a supermembrane with manifest supersymmetry and duality symmetry is
proposed. This quantization provides a natural quantum mechanical description
of curved BPS-type backgrounds related to the ultra-short supersymmetry
multiplets. Half-size commuting and anticommuting Killing spinors admitted by
such backgrounds in quantum theory become truncated -symmetry ghosts.
The symmetry of Killing spinors under dualities transfers to the symmetry of
the spectrum of states.
GS superstring in the generalized semi-light-cone gauge can be quantized
consistently in the background of ten-dimensional supersymmetric gravitational
waves. Upon compactification they become supersymmetric electrically charged
black holes, either massive or massless. However, the generalized light-cone
gauge breaks S-duality. We propose a new family of gauges, which we call black
hole gauges. These gauges are suitable for quantization both in flat Minkowski
space and in the black hole background, and they are duality symmetric. As an
example, a manifestly S-duality symmetric black hole gauge is constructed in
terms of the axion-dilaton-electric-magnetic black hole hair. We also suggest
the U-duality covariant class of gauges for type II superstrings.Comment: 49 pages, LaTe
Supersymmetry of the 2+1 black holes
The supersymmetry properties of the asymptotically anti-de Sitter black holes
of Einstein theory in 2+1 dimensions are investigated. It is shown that (i) the
zero mass black hole has two exact super- symmetries; (ii) extreme
black holes with have only one; and (iii) generic black holes do
not have any. It is also argued that the zero mass hole is the ground state of
(1,1)-adS supergravity with periodic (``Ramond") boundary conditions on the
spinor fields.Comment: 9 pages LaTeX file, ULB-PMIF-93/0