84 research outputs found
Black Hole Hair Removal: Non-linear Analysis
BMPV black holes in flat transverse space and in Taub-NUT space have
identical near horizon geometries but different microscopic degeneracies. It
has been proposed that this difference can be accounted for by different
contribution to the degeneracies of these black holes from hair modes, --
degrees of freedom living outside the horizon. In this paper we explicitly
construct the hair modes of these two black holes as finite bosonic and
fermionic deformations of the black hole solution satisfying the full
non-linear equations of motion of supergravity and preserving the supersymmetry
of the original solutions. Special care is taken to ensure that these solutions
do not have any curvature singularity at the future horizon when viewed as the
full ten dimensional geometry. We show that after removing the contribution due
to the hair degrees of freedom from the microscopic partition function, the
partition functions of the two black holes agree.Comment: 40 pages, LaTe
Supersymmetric String Waves
We present plane-wave-type solutions of the lowest order superstring
effective action which have unbroken space-time supersymmetries. They describe
dilaton, axion and gauge fields in a stringy generalization of the Brinkmann
metric. Some conspiracy between the metric and the axion field is required. We
show that there exists a special class of these solutions, for which
stringy corrections to the effective on-shell action, to the
equations of motion (and therefore to the solutions themselves), and to the
supersymmetry transformations vanish. We call these solutions supersymmetric
string waves (SSW).Comment: 19 pages, LaTeX, SU-ITP-92-30 and UG-10/9
New Solution of D=11 Supergravity on S^7 from D=4
A new static partially twisted solution of N=4, SO(4) gauged supergravity in
D=11 is obtained in this work using Cveti\^c et al embedding of four
dimensional into eleven dimensional supergravities. In four dimensions we get
two solutions: an asymptotic one corresponding to and a near horizon
fixed point solution of the form . Hence, while the former
solution has 32 supercharges the latter turns out to have only 4 conserved.
Moreover, we managed to find an exact interpolating solution, thus connecting
the above two. Aiming at a future study of duality for the theory at
hand we derived the Penrose limit of the four dimensional solutions.
Interestingly the pp-wave limit of the near horizon solution suggests itself as
being of the supernumerary supersymmetric type. In D=11 we exhibit the uplift
of the four dimensional solutions: one associated to and the
other to a foliation of , as well as their pp-wave
limits.Comment: 14 pages, LaTe
Generalized Geometry and Partial Supersymmetry Breaking
This review article consists of two parts. In the first part we use the
formalism of (exceptional) generalized geometry to derive the scalar field
space of SU(2)xSU(2)-structure compactifications. We show that in contrast to
SU(3)xSU(3) structures, there is no dynamical SU(2)xSU(2) structure
interpolating between an SU(2) structure and an identity structure.
Furthermore, we derive the scalar manifold of the low-energy effective action
for consistent Kaluza-Klein truncations as expected from N=4 supergravity.
In the second part we then determine the general conditions for the existence
of stable Minkowski and AdS N=1 vacua in spontaneously broken gauged N=2
supergravities and construct the general solution under the assumption that two
appropriate commuting isometries exist in the hypermultiplet sector.
Furthermore, we derive the low-energy effective action below the scale of
partial supersymmetry breaking and show that it satisfies the constraints of
N=1 supergravity. We then apply the discussion to special quaternionic-Kahler
geometries which appear in the low-energy limit of SU(3)xSU(3)-structure
compactifications and construct Killing vectors with the right properties.
Finally we discuss the string theory realizations for these solutions.Comment: 117 pages, Ph.D. thesis (Advisor: Jan Louis); v2: references adde
Structure in 6D and 4D N=1 supergravity theories from F-theory
We explore some aspects of 4D supergravity theories and F-theory vacua that
are parallel to structures in the space of 6D theories. The spectrum and
topological terms in 4D supergravity theories correspond to topological data of
F-theory geometry, just as in six dimensions. In particular, topological
axion-curvature squared couplings appear in 4D theories; these couplings are
characterized by vectors in the dual to the lattice of axion shift symmetries
associated with string charges. These terms are analogous to the Green-Schwarz
terms of 6D supergravity theories, though in 4D the terms are not generally
linked with anomalies. We outline the correspondence between F-theory topology
and data of the corresponding 4D supergravity theories. The correspondence of
geometry with structure in the low-energy action illuminates topological
aspects of heterotic-F-theory duality in 4D as well as in 6D. The existence of
an F-theory realization also places geometrical constraints on the 4D
supergravity theory in the large-volume limit.Comment: 63 page
Supersymmetry, Localization and Quantum Entropy Function
AdS_2/CFT_1 correspondence leads to a prescription for computing the
degeneracy of black hole states in terms of path integral over string fields
living on the near horizon geometry of the black hole. In this paper we make
use of the enhanced supersymmetries of the near horizon geometry and
localization techniques to argue that the path integral receives contribution
only from a special class of string field configurations which are invariant
under a subgroup of the supersymmetry transformations. We identify saddle
points which are invariant under this subgroup. We also use our analysis to
show that the integration over infinite number of zero modes generated by the
asymptotic symmetries of AdS_2 generate a finite contribution to the path
integral.Comment: LaTeX file, 31 pages; v2: minor correction; v3: typos correcte
Exploring Three-dimensional Higher-Spin Supergravity based on sl(N |N - 1) Chern-Simons theories
We investigate various aspects of higher-spin anti-de Sitter supergravity in
three dimensions as described by Chern-Simons theory based on the
finite-dimensional superalgebra sl(N |N - 1), with the particular case of N = 3
as our prime example. This class of theories serves as a natural
supersymmetrization of the higher-spin gravity theory based on sl(N)
Chern-Simons theories. We demonstrate explicitly that the asymptotic symmetry
algebra contains the N = 2 superconformal algebra in each sector. The
appropriate Killing spinor equations are derived and used to classify existing
and new classical solutions. We also discuss holonomy conditions, higher-spin
black holes and conical defect spacetimes in this class of theories.Comment: 41 pages, a few typos in v4 correcte
Revisiting Gender Differences in Somatic Symptoms of Depression: Much Ado about Nothing?
Women have a higher prevalence of Major Depressive Disorder (MDD) and report more severe depressive symptoms than men. Several studies have suggested that gender differences in depression may occur because women report higher levels of somatic symptoms than men. Those studies, however, have not controlled or matched for non-somatic symptoms. The objective of this study was to examine if women report relatively more somatic symptoms than men matched on cognitive/affective symptoms.Male and female patients receiving treatment for MDD in outpatient psychiatric clinics in New Jersey and Pennsylvania, USA were matched on Beck Depression Inventory-II (BDI-II) cognitive/affective symptom scores. Male and female BDI-II somatic symptom scores were compared using independent samples 2-tailed t-tests.Of 472 male and 1,026 female patients, there were 470 male patients (mean age = 40.1 years, SD = 15.1) and 470 female patients (mean age = 43.1 years, SD = 17.2) successfully matched on BDI-II cognitive/affective symptom scores. Somatic symptoms accounted for 35% of total BDI-II scores for male patients versus 38% for matched female patients. Female patients had somatic symptom scores on average 1.3 points higher than males (p<.001), equivalent to 4% of the total BDI-II scores of female patients. Only 5% of male patients and 7% of female patients scored 2 or higher on all BDI-II somatic symptom items.Gender differences in somatic scores were very small. Thus, differences in the experience and reporting of somatic symptoms would not likely explain gender differences in depression rates and symptom severity
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