134 research outputs found
Evidence for a family of SO(8) gauged supergravity theories
In this note we discuss the classification of duality orbits of N = 8 gauged
supergravity models. Using tensor classifiers, we show that there is a
one-parameter family of inequivalent SO(8) gauged supergravity theories. We
briefly discuss the couplings of such models and show that, although the
maximally symmetric vacuum has the same quadratic spectrum, the supersymmetry
transformations, the couplings and the scalar potential are parameter
dependent. We also comment on the possible M-theory uplift and on the meaning
of the parameter for the dual gauge theories.Comment: 5 pages, 2 figures. v2: improved presentation. References fixe
Symmetry-deforming interactions of chiral p-forms
No-go theorems on gauge-symmetry-deforming interactions of chiral p-forms are
reviewed. We consider the explicit case of p=4, D=10 and show that the only
symmetry-deforming consistent vertex for a system of one chiral 4-form and two
2-forms is the one that occurs in the type II B supergravity Lagrangian.Comment: 7 pages, tiny typo corrections, based on a talk given by M. H. at the
conference "Constrained Dynamics and Quantum Gravity " held in Villasimius
(Sardinia), September 13-17 1999, to appear in the proceedings of the meeting
(Nucl. Phys. B Proc. Suppl.
E_{7(7)} symmetry and dual gauge algebra of M-theory on a twisted seven-torus
We consider M-theory compactified on a twisted 7-torus with fluxes when all
the seven antisymmetric tensor fields in four dimensions have been dualized
into scalars and thus the E_{7(7)} symmetry is recovered. We find that the
Scherk--Schwarz and flux gaugings define a ``dual'' gauge algebra, subalgbra of
E_{7(7)}, where some of the generators are associated with vector fields which
are dual to part of the original vector fields (deriving from the 3-form). In
particular they are dual to those vector fields which have been ``eaten'' by
the antisymmetric tensors in the original theory by the (anti-)Higgs mechanism.
The dual gauge algebra coincides with the original gauge structure when the
quotient with respect to these dual (broken) gauge generators is taken. The
particular example of the S-S twist corresponding to a ``flat group'' is
considered.Comment: 12 pages, LaTeX file, typos corrected, references added, some
discussions extende
Non-Kaehler attracting manifolds
We observe that the new attractor mechanism describing IIB flux vacua for
Calabi-Yau compactifications has a possible extension to the landscape of
non-Kaehler vacua that emerge in heterotic compactifications with fluxes. We
focus on the effective theories coming from compactifications on generalized
half-flat manifolds, showing that the Minkowski "attractor points'' for 3-form
fluxes are special-hermitian manifolds.Comment: 18 pages. v2: Minor polishing, reference added. v3: More cleanup,
final version for JHE
Chiral Zeromodes on Vortex-type Intersecting Heterotic Five-branes
We solve the gaugino Dirac equation on a smeared intersecting five-brane
solution in E_8\times E_8 heterotic string theory to search for localized
chiral zeromodes on the intersection. The background is chosen to depend on the
full two-dimensional overall transverse coordinates to the branes. Under some
appropriate boundary conditions, we compute the complete spectrum of zeromodes
to find that, among infinite towers of Fourier modes, there exist only three
localized normalizable zeromodes, one of which has opposite chirality to the
other two. This agrees with the result previously obtained in the domain-wall
type solution, supporting the claim that there exists one net chiral zeromode
localized on the heterotic five-brane system.Comment: 10 pages, 2 figure
Scalar potential for the gauged Heisenberg algebra and a non-polynomial antisymmetric tensor theory
We study some issues related to the effective theory of Calabi-Yau
compactifications with fluxes in Type II theories. At first the scalar
potential for a generic electric abelian gauging of the Heisenberg algebra,
underlying all possible gaugings of RR isometries, is presented and shown to
exhibit, in some circumstances, a "dual'' no-scale structure under the
interchange of hypermultiplets and vector multiplets. Subsequently a new
setting of such theories, when all RR scalars are dualized into antisymmetric
tensors, is discussed. This formulation falls in the class of non-polynomial
tensor theories considered long ago by Freedman and Townsend and it may be
relevant for the introduction of both electric and magnetic charges.Comment: 11 pages LaTe
Towards reduction of type II theories on SU(3) structure manifolds
We revisit the reduction of type II supergravity on SU(3) structure
manifolds, conjectured to lead to gauged N=2 supergravity in 4 dimensions. The
reduction proceeds by expanding the invariant 2- and 3-forms of the SU(3)
structure as well as the gauge potentials of the type II theory in the same set
of forms, the analogues of harmonic forms in the case of Calabi-Yau reductions.
By focussing on the metric sector, we arrive at a list of constraints these
expansion forms should satisfy to yield a base point independent reduction.
Identifying these constraints is a first step towards a first-principles
reduction of type II on SU(3) structure manifolds.Comment: 20 pages; v2: condition (2.13old) on expansion forms weakened,
replaced by (2.13new), (2.14new
Dirac equation for the supermembrane in a background with fluxes from a component description of the D=11 supergravity-supermembrane interacting system
We present a simple derivation of the 'Dirac' equation for the supermembrane
fermionic field in a D=11 supergravity background with fluxes by using a
complete but gauge-fixed description of the supergravity-supermembrane
interacting system previously developed. We also discuss the contributions
linear in the supermembrane fermions -the Goldstone fields for the local
supersymmetry spontaneously broken by the superbrane- to the field equations of
the supergravity-supermembrane interacting system. The approach could also be
applied to more complicated dynamical systems such as those involving the
M5-brane and the D=10 Dirichlet branes.Comment: 1+22 pages, JHEP style. v2: cosmetic changes and references added to
conform to the JHEP published versio
Twisted tori and fluxes: a no go theorem for Lie groups of weak G_2 holonomy
In this paper we prove the theorem that there exists no 7--dimensional Lie
group manifold G of weak G2 holonomy.
We actually prove a stronger statement, namely that there exists no
7--dimensional Lie group with negative definite Ricci tensor Ric_{IJ}.
This result rules out (supersymmetric and non--supersymmetric)
Freund--Rubin solutions of M--theory of the form AdS_4\times G and
compactifications with non--trivial 4--form fluxes of Englert type on an
internal group manifold G. A particular class of such backgrounds which, by our
arguments are excluded as bulk supergravity compactifications corresponds to
the so called compactifications on twisted--tori, for which G has structure
constants with vanishing trace . On the other
hand our result does not have bearing on warped compactifications of M--theory
to four dimensions and/or to compactifications in the presence of localized
sources (D--branes, orientifold planes and so forth). Henceforth our result
singles out the latter compactifications as the preferred hunting grounds that
need to be more systematically explored in relation with all compactification
features involving twisted tori.Comment: 38 pages, tar file containing LaTeX source and youngtab.st
The Three Dimensional Dual of 4D Chirality
Chiral gauge theories can be defined in four-dimensional Anti de Sitter
space, but AdS boundary conditions explicitly break the chiral symmetry in a
specific, well defined manner, which in turns results in an anomalous Ward
identity. When the 4D theory admits a dual description in terms of a 3D CFT,
the 3D dual of the broken chiral symmetry is a certain double-trace deformation
of the CFT, which produces the same anomalous chiral Ward identities that
obtains in the 4D bulk theory.Comment: 10 pages, small misprints corrected, reference [16] updated. Version
to appear in JHE
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