9,186 research outputs found
Consistent truncation of d = 11 supergravity on AdS_4 x S^7
We study the system of equations derived twenty five years ago by B. de Wit
and the first author [Nucl. Phys. B281 (1987) 211] as conditions for the
consistent truncation of eleven-dimensional supergravity on AdS_4 x S^7 to
gauged N = 8 supergravity in four dimensions. By exploiting the E_7(7)
symmetry, we determine the most general solution to this system at each point
on the coset space E_7(7)/SU(8). We show that invariants of the general
solution are given by the fluxes in eleven-dimensional supergravity. This
allows us to both clarify the explicit non-linear ansatze for the fluxes given
previously and to fill a gap in the original proof of the consistent
truncation. These results are illustrated with several examples.Comment: 41 pages, typos corrected, published versio
E7(7) invariant Lagrangian of d=4 N=8 supergravity
We present an E7(7) invariant Lagrangian that leads to the equations of
motion of d=4 N=8 supergravity without using Lagrange multipliers. The
superinvariance of this new action and the closure of the supersymmetry algebra
are proved explicitly for the terms that differ from the Cremmer--Julia
formulation. Since the diffeomorphism symmetry is not realized in the standard
way on the vector fields, we switch to the Hamiltonian formulation in order to
prove the invariance of the E7(7) invariant action under general coordinate
transformations. We also construct the conserved E7(7)-Noether current of
maximal supergravity and we conclude with comments on the implications of this
manifest off-shell E7(7)-symmetry for quantizing d=4 N=8 supergravity, in
particular on the E7(7)-action on phase space.Comment: 45 pages, references adde
The Tensor Hierarchies of Pure N=2,d=4,5,6 Supergravities
We study the supersymmetric tensor hierarchy of pure (gauged) N=2,d=4,5,6
supergravity and compare them with those of the pure, ungauged, theories
(worked out by Gomis and Roest for d=5) and the predictions of the Kac-Moody
approach made by Kleinschmidt and Roest. We find complete agreement in the
ungauged case but we also find that, after gauging, new Stueckelberg symmetries
reduce the number of independent "physical" top-forms. The analysis has to be
performed to all orders in fermion fields.
We discuss the construction of the worldvolume effective actions for the
p-branes which are charged with respect to the (p+1)-form potentials and the
relations between the tensor hierarchies and p-branes upon dimensional
reduction.Comment: LaTeX2e file, 20 pages, 1 figure Results refined by extension of the
analysis to all orders in fermion
A Massive S-duality in 4 dimensions
We reduce the Type IIA supergravity theory with a generalized Scherk-Schwarz
ansatz that exploits the scaling symmetry of the dilaton, the metric and the NS
2-form field. The resulting theory is a new massive, gauged supergravity theory
in four dimensions with a massive 2-form field and a massive 1-form field. We
show that this theory is S-dual to a theory with a massive vector field and a
massive 2-form field, which are dual to the massive 2-form and 1-form fields in
the original theory, respectively. The S-dual theory is shown to arise from a
Scherk-Schwarz reduction of the heterotic theory. Hence we establish a massive,
S-duality type relation between the IIA theory and the heterotic theory in four
dimensions. We also show that the Lagrangian for the new four dimensional
theory can be put in the most general form of a D=4, N=4 gauged Lagrangian
found by Schon and Weidner, in which (part of) the SL(2) group has been gauged.Comment: 20 pages, references adde
Transverse nucleon structure and diagnostics of hard parton-parton processes at LHC
We propose a new method to determine at what transverse momenta particle
production in high-energy pp collisions is governed by hard parton-parton
processes. Using information on the transverse spatial distribution of partons
obtained from hard exclusive processes in ep/gamma p scattering, we evaluate
the impact parameter distribution of pp collisions with a hard parton-parton
process as a function of p_T of the produced parton (jet). We find that the
average pp impact parameters in such events depend very weakly on p_T in the
range 2 < p_T < few 100 GeV, while they are much smaller than those in
minimum-bias inelastic collisions. The impact parameters in turn govern the
observable transverse multiplicity in such events (in the direction
perpendicular to the trigger particle or jet). Measuring the transverse
multiplicity as a function of p_T thus provides an effective tool for
determining the minimum p_T for which a given trigger particle originates from
a hard parton-parton process. Additional tests of the proposed geometric
correlations are possible by measuring the dependence on the trigger rapidity.
Various strategies for implementing this method are outlined.Comment: 9 pages, 6 figure
Strong Couplings of X(3872)_{J=1,2} and a New Look at J/psi Suppression in Heavy Ion Collisions
We define and compute from data the strong couplings of the X(3872) with both
of the possible quantum numbers assignments J^{PC}=1^{++},2^{-+}. We use these
to compute cross sections for J/psi resonance scattering into D Dbar*. As an
application of the results obtained we revise the calculation of the J/psi
absorption in a hot hadron gas to confront with recent RHIC observations in
Au-Au collisions.Comment: 23 pages, 18 figures, 4 table
Completeness in supergravity constructions
We prove that the supergravity r- and c-maps preserve completeness. As a
consequence, any component H of a hypersurface {h=1} defined by a homogeneous
cubic polynomial such that -d^2 h is a complete Riemannian metric on H defines
a complete projective special Kahler manifold and any complete projective
special Kahler manifold defines a complete quaternionic Kahler manifold of
negative scalar curvature. We classify all complete quaternionic Kahler
manifolds of dimension less or equal to 12 which are obtained in this way and
describe some complete examples in 16 dimensions.Comment: 29 page
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
N=2 supergravity in five dimensions revisited
We construct matter-coupled N=2 supergravity in five dimensions, using the
superconformal approach. For the matter sector we take an arbitrary number of
vector-, tensor- and hyper-multiplets. By allowing off-diagonal vector-tensor
couplings we find more general results than currently known in the literature.
Our results provide the appropriate starting point for a systematic search for
BPS solutions, and for applications of M-theory compactifications on Calabi-Yau
manifolds with fluxes.Comment: 35 pages; v.2: A sign changed in a bilinear fermion term in (5.7
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