3,413 research outputs found
Venting device for pressurized space suit helmet Patent
Venting device for pressurized space suit helmet to eliminate vomit expelled by crewme
The supersymmetric solutions and extensions of ungauged matter-coupled N=1,d=4 supergravity
We find the most general supersymmetric solutions of ungauged N=1,d=4
supergravity coupled to an arbitrary number of vector and chiral
supermultiplets, which turn out to be essentially pp-waves and strings. We also
introduce magnetic 1-forms and their supersymmetry transformations and 2-forms
associated to the isometries of the scalar manifold and their supersymmetry
transformations. Only the latter can couple to BPS objects (strings), in
agreement with our results.Comment: Some misprints and citations correcte
Invariant Killing spinors in 11D and type II supergravities
We present all isotropy groups and associated groups, up to discrete
identifications of the component connected to the identity, of spinors of
eleven-dimensional and type II supergravities. The groups are products
of a Spin group and an R-symmetry group of a suitable lower dimensional
supergravity theory. Using the case of SU(4)-invariant spinors as a paradigm,
we demonstrate that the groups, and so the R-symmetry groups of
lower-dimensional supergravity theories arising from compactifications, have
disconnected components. These lead to discrete symmetry groups reminiscent of
R-parity. We examine the role of disconnected components of the groups
in the choice of Killing spinor representatives and in the context of
compactifications.Comment: 22 pages, typos correcte
Characterization of all the supersymmetric solutions of gauged N=1,d=5 supergravity
We find a complete characterization of all the supersymmetric solutions of
non-Abelian gauged N=1,d=5 supergravity coupled to vector multiplets and
hypermultiplets: the generic forms of the metrics as functions of the scalars
and vector fields plus the equations that all these must satisfy. These
equations are now a complicated non-linear system and there it seems impossible
to produce an algorithm to construct systematically all supersymmetric
solutions.Comment: Some references and two comments adde
All the timelike supersymmetric solutions of all ungauged d=4 supergravities
We determine the form of all timelike supersymmetric solutions of all N
greater or equal than 2, d=4 ungauged supergravities, for N less or equal than
4 coupled to vector supermultiplets, using the $Usp(n+1,n+1)-symmetric
formulation of Andrianopoli, D'Auria and Ferrara and the spinor-bilinears
method, while preserving the global symmetries of the theories all the way. As
previously conjectured in the literature, the supersymmetric solutions are
always associated to a truncation to an N=2 theory that may include
hypermultiplets, although fields which are eliminated in the truncations can
have non-trivial values, as is required by the preservation of the global
symmetry of the theories. The solutions are determined by a number of
independent functions, harmonic in transverse space, which is twice the number
of vector fields of the theory (n+1). The transverse space is flat if an only
if the would-be hyperscalars of the associated N=2 truncation are trivial.Comment: v3: Some changes in the introduction. Version to be published in JHE
All null supersymmetric backgrounds of N=2, D=4 gauged supergravity coupled to abelian vector multiplets
The lightlike supersymmetric solutions of N=2, D=4 gauged supergravity
coupled to an arbitrary number of abelian vector multiplets are classified
using spinorial geometry techniques. The solutions fall into two classes,
depending on whether the Killing spinor is constant or not. In both cases, we
give explicit examples of supersymmetric backgrounds. Among these BPS
solutions, which preserve one quarter of the supersymmetry, there are
gravitational waves propagating on domain walls or on bubbles of nothing that
asymptote to AdS_4. Furthermore, we obtain the additional constraints obeyed by
half-supersymmetric vacua. These are divided into four categories, that include
bubbles of nothing which are asymptotically AdS_4, pp-waves on domain walls,
AdS_3 x R, and spacetimes conformal to AdS_3 times an interval.Comment: 55 pages, uses JHEP3.cls. v2: Minor errors corrected, small changes
in introductio
Supersymmetric solutions of gauged five-dimensional supergravity with general matter couplings
We perform the characterization program for the supersymmetric configurations
and solutions of the , Supergravity Theory coupled to an
arbitrary number of vectors, tensors and hypermultiplets and with general
non-Abelian gaugins. By using the conditions yielded by the characterization
program, new exact supersymmetric solutions are found in the
model for the hyperscalars and with as the gauge group. The
solutions also content non-trivial vector and massive tensor fields, the latter
being charged under the U(1) sector of the gauge group and with selfdual
spatial components. These solutions are black holes with
near horizon geometry in the gauged version of the theory and for the ungauged
case we found naked singularities. We also analyze supersymmetric solutions
with only the scalars of the vector/tensor multiplets and the metric
as the non-trivial fields. We find that only in the null class the scalars
can be non-constant and for the case of constant we refine
the classification in terms of the contributions to the scalar potential.Comment: Minor changes in wording and some typos corrected. Version to appear
in Class. Quantum Grav. 38 page
Solar ionizing flux as determined from sunrise measurements of electron content
Solar ionizing flux from sunrise measurements of electron conten
Spinorial geometry and Killing spinor equations of 6-D supergravity
We solve the Killing spinor equations of 6-dimensional (1,0)-supergravity
coupled to any number of tensor, vector and scalar multiplets in all cases. The
isotropy groups of Killing spinors are Sp(1)\cdot Sp(1)\ltimes \bH (1),
U(1)\cdot Sp(1)\ltimes \bH (2), Sp(1)\ltimes \bH (3,4), , and , where in parenthesis is the number of supersymmetries
preserved in each case. If the isotropy group is non-compact, the spacetime
admits a parallel null 1-form with respect to a connection with torsion the
3-form field strength of the gravitational multiplet. The associated vector
field is Killing and the 3-form is determined in terms of the geometry of
spacetime. The Sp(1)\ltimes \bH case admits a descendant solution preserving
3 out of 4 supersymmetries due to the hyperini Killing spinor equation. If the
isotropy group is compact, the spacetime admits a natural frame constructed
from 1-form spinor bi-linears. In the and U(1) cases, the spacetime
admits 3 and 4 parallel 1-forms with respect to the connection with torsion,
respectively. The associated vector fields are Killing and under some
additional restrictions the spacetime is a principal bundle with fibre a
Lorentzian Lie group. The conditions imposed by the Killing spinor equations on
all other fields are also determined.Comment: 34 pages, Minor change
The spinorial geometry of supersymmetric heterotic string backgrounds
We determine the geometry of supersymmetric heterotic string backgrounds for
which all parallel spinors with respect to the connection with
torsion , the NSNS three-form field strength, are Killing. We find
that there are two classes of such backgrounds, the null and the timelike. The
Killing spinors of the null backgrounds have stability subgroups
K\ltimes\bR^8 in , for , SU(4), , and , and the Killing spinors of the timelike backgrounds have
stability subgroups , SU(3), SU(2) and . The former admit a single
null -parallel vector field while the latter admit a timelike and
two, three, five and nine spacelike -parallel vector fields,
respectively. The spacetime of the null backgrounds is a Lorentzian
two-parameter family of Riemannian manifolds with skew-symmetric torsion.
If the rotation of the null vector field vanishes, the holonomy of the
connection with torsion of is contained in . The spacetime of time-like
backgrounds is a principal bundle with fibre a Lorentzian Lie group and
base space a suitable Riemannian manifold with skew-symmetric torsion. The
principal bundle is equipped with a connection which determines the
non-horizontal part of the spacetime metric and of . The curvature of
takes values in an appropriate Lie algebra constructed from that of
. In addition has only horizontal components and contains the
Pontrjagin class of . We have computed in all cases the Killing spinor
bilinears, expressed the fluxes in terms of the geometry and determine the
field equations that are implied by the Killing spinor equations.Comment: 73pp. v2: minor change
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