33 research outputs found
Minimal Stability in Maximal Supergravity
Recently, it has been shown that maximal supergravity allows for
non-supersymmetric AdS critical points that are perturbatively stable. We
investigate this phenomenon of stability without supersymmetry from the
sGoldstino point of view. In particular, we calculate the projection of the
mass matrix onto the sGoldstino directions, and derive the necessary conditions
for stability. Indeed we find a narrow window allowing for stable SUSY breaking
points. As a by-product of our analysis, we find that it seems impossible to
perturb supersymmetric critical points into non-supersymmetric ones: there is a
minimal amount of SUSY breaking in maximal supergravity.Comment: 27 pages, 1 figure. v2: two typos corrected, published versio
Duality Invariant M-theory: Gauged supergravities and Scherk-Schwarz reductions
We consider the reduction of the duality invariant approach to M-theory by a
U-duality group valued Scherk-Schwarz twist. The result is to produce
potentials for gauged supergravities that are normally associated with
non-geometric compactifications. The local symmetry reduces to gauge
transformations with the gaugings exactly matching those of the embedding
tensor approach to gauged supergravity. Importantly, this approach now includes
a nontrivial dependence of the fields on the extra coordinates of the extended
space.Comment: 22 pages Latex; v2: typos corrected and references adde
Critical points of maximal D=8 gauged supergravities
We study the general deformations of maximal eight-dimensional supergravity
by using the embedding tensor approach. The scalar potential induced by these
gaugings is determined. Subsequently, by combining duality covariance arguments
and algebraic geometry techniques, we find the complete set of critical points
of the scalar potential. Remarkably, up to SO(2) X SO(3) rotations there turns
out to be a unique theory admitting extrema. The gauge group of the theory is
CSO(2,0,1).Comment: 14 pages. v2: minor changes - published versio
Lectures on Gauged Supergravity and Flux Compactifications
The low-energy effective theories describing string compactifications in the
presence of fluxes are so-called gauged supergravities: deformations of the
standard abelian supergravity theories. The deformation parameters can be
identified with the various possible (geometric and non-geometric) flux
components. In these lecture notes we review the construction of gauged
supergravities in a manifestly duality covariant way and illustrate the
construction in several examples.Comment: 48 pages, lectures given at the RTN Winter School on Strings,
Supergravity and Gauge Theories, CERN, January 200
E10 and Gauged Maximal Supergravity
We compare the dynamics of maximal three-dimensional gauged supergravity in
appropriate truncations with the equations of motion that follow from a
one-dimensional E10/K(E10) coset model at the first few levels. The constant
embedding tensor, which describes gauge deformations and also constitutes an
M-theoretic degree of freedom beyond eleven-dimensional supergravity, arises
naturally as an integration constant of the geodesic model. In a detailed
analysis, we find complete agreement at the lowest levels. At higher levels
there appear mismatches, as in previous studies. We discuss the origin of these
mismatches.Comment: 34 pages. v2: added references and typos corrected. Published versio
Exceptional Flux Compactifications
We consider type II (non-)geometric flux backgrounds in the absence of brane
sources, and construct their explicit embedding into maximal gauged D=4
supergravity. This enables one to investigate the critical points, mass spectra
and gauge groups of such backgrounds. We focus on a class of type IIA geometric
vacua and find a novel, non-supersymmetric and stable AdS vacuum in maximal
supergravity with a non-semisimple gauge group. Our construction relies on a
non-trivial mapping between SL(2) x SO(6,6) fluxes, SU(8) mass spectra and
gaugings of E7(7) subgroups.Comment: 51 pages, 2 figures and 4 tables. v3: change of SO(6,6) spinorial
conventions, published versio