162 research outputs found
Leibniz Gauge Theories and Infinity Structures
We formulate gauge theories based on Leibniz(-Loday) algebras and uncover
their underlying mathematical structure. Various special cases have been
developed in the context of gauged supergravity and exceptional field theory.
These are based on `tensor hierarchies', which describe towers of -form
gauge fields transforming under non-abelian gauge symmetries and which have
been constructed up to low levels. Here we define `infinity-enhanced Leibniz
algebras' that guarantee the existence of consistent tensor hierarchies to
arbitrary level. We contrast these algebras with strongly homotopy Lie algebras
( algebras), which can be used to define topological field theories
for which all curvatures vanish. Any infinity-enhanced Leibniz algebra carries
an associated algebra, which we discuss.Comment: 50 pages, v2: refs added, new subsection 3.2, version to appear in
Comm. Math. Phy
Perturbative Double Field Theory on General Backgrounds
We develop the perturbation theory of double field theory around arbitrary
solutions of its field equations. The exact gauge transformations are written
in a manifestly background covariant way and contain at most quadratic terms in
the field fluctuations. We expand the generalized curvature scalar to cubic
order in fluctuations and thereby determine the cubic action in a manifestly
background covariant form. As a first application we specialize this theory to
group manifold backgrounds, such as with -flux. In the
full string theory this corresponds to a WZW background CFT. Starting from
closed string field theory, the cubic action around such backgrounds has been
computed before by Blumenhagen, Hassler and L\"ust. We establish precise
agreement with the cubic action derived from double field theory. This result
confirms that double field theory is applicable to arbitrary curved background
solutions, disproving assertions in the literature to the contrary.Comment: 36 pages, v2: minor clarification
U-duality covariant gravity
We extend the techniques of double field theory to more general gravity
theories and U-duality symmetries, having in mind applications to the complete
D=11 supergravity. In this paper we work out a (3+3)-dimensional `U-duality
covariantization' of D=4 Einstein gravity, in which the Ehlers group SL(2,R) is
realized geometrically, acting in the 3 representation on half of the
coordinates. We include the full (2+1)-dimensional metric, while the `internal
vielbein' is a coset representative of SL(2,R)/SO(2) and transforms under gauge
transformations via generalized Lie derivatives. In addition, we introduce a
gauge connection of the `C-bracket', and a gauge connection of SL(2,R), albeit
subject to constraints. The action takes the form of (2+1)-dimensional gravity
coupled to a Chern-Simons-matter theory but encodes the complete D=4 Einstein
gravity. We comment on generalizations, such as an `
covariantization' of M-theory.Comment: 36 pages, v2: refs. added, to appear in JHE
AdS_3/LCFT_2 - Correlators in New Massive Gravity
We calculate 2-point correlators for New Massive Gravity at the chiral point
and find that they behave precisely as those of a logarithmic conformal field
theory, which is characterized in addition to the central charges c_L = c_R = 0
by `new anomalies' b_L = b_R = -\sigma\frac{12\ell}{G_N}, where \sigma is the
sign of the Einstein-Hilbert term, \ell the AdS radius and G_N Newton's
constant.Comment: 10 pages, v2: incorrect statement in conclusions deleted, reference
added, v3: version to appear in Phys. Lett.
Towards an invariant geometry of double field theory
We introduce a geometrical framework for double field theory in which
generalized Riemann and torsion tensors are defined without reference to a
particular basis. This invariant geometry provides a unifying framework for the
frame-like and metric-like formulations developed before. We discuss the
relation to generalized geometry and give an `index-free' proof of the
algebraic Bianchi identity. Finally, we analyze to what extent the generalized
Riemann tensor encodes the curvatures of Riemannian geometry. We show that it
contains the conventional Ricci tensor and scalar curvature but not the full
Riemann tensor, suggesting the possibility of a further extension of this
framework.Comment: 44 pages, v2: refs. improved, minor corrections, to appear in J.
Math. Phy
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