204 research outputs found
Massive Type II in Double Field Theory
We provide an extension of the recently constructed double field theory
formulation of the low-energy limits of type II strings, in which the RR fields
can depend simultaneously on the 10-dimensional space-time coordinates and
linearly on the dual winding coordinates. For the special case that only the RR
one-form of type IIA carries such a dependence, we obtain the massive
deformation of type IIA supergravity due to Romans. For T-dual configurations
we obtain a `massive' but non-covariant formulation of type IIB, in which the
10-dimensional diffeomorphism symmetry is deformed by the mass parameter.Comment: 21 page
A Double Sigma Model for Double Field Theory
We define a sigma model with doubled target space and calculate its
background field equations. These coincide with generalised metric equation of
motion of double field theory, thus the double field theory is the effective
field theory for the sigma model.Comment: 26 pages, v1: 37 pages, v2: references added, v3: updated to match
published version - background and detail of calculations substantially
condensed, motivation expanded, refs added, results unchange
On Maximal Massive 3D Supergravity
We construct, at the linearized level, the three-dimensional (3D) N = 4
supersymmetric "general massive supergravity" and the maximally supersymmetric
N = 8 "new massive supergravity". We also construct the maximally
supersymmetric linearized N = 7 topologically massive supergravity, although we
expect N = 6 to be maximal at the non-linear level.Comment: 33 page
Lorentz Violation of Quantum Gravity
A quantum gravity theory which becomes renormalizable at short distances due
to a spontaneous symmetry breaking of Lorentz invariance and diffeomorphism
invariance is studied. A breaking of Lorentz invariance with the breaking
patterns and , describing 3+1 and 2+1
quantum gravity, respectively, is proposed. A complex time dependent
Schr\"odinger equation (generalized Wheeler-DeWitt equation) for the wave
function of the universe exists in the spontaneously broken symmetry phase at
Planck energy and in the early universe, uniting quantum mechanics and general
relativity. An explanation of the second law of thermodynamics and the
spontaneous creation of matter in the early universe can be obtained in the
symmetry broken phase of gravity.Comment: 10 pages, minor change and reference added. Typos corrected. To be
published in Class. Quant. Grav
Effective Actions for Massive Kaluza-Klein States on AdS_3 x S^3 x S^3
We construct the effective supergravity actions for the lowest massive
Kaluza-Klein states on the supersymmetric background AdS_3 x S^3 x S^3. In
particular, we describe the coupling of the supergravity multiplet to the
lowest massive spin-3/2 multiplet which contains 256 physical degrees of
freedom and includes the moduli of the theory. The effective theory is realized
as the broken phase of a particular gauging of the maximal three-dimensional
supergravity with gauge group SO(4) x SO(4). Its ground state breaks half of
the supersymmetries leading to 8 massive gravitinos acquiring mass in a super
Higgs effect. The holographic boundary theory realizes the large N=(4,4)
superconformal symmetry.Comment: 31 pages, v2: minor change
Global aspects of double geometry
We consider the concept of a generalised manifold in the O(d,d) setting,
i.e., in double geometry. The conjecture by Hohm and Zwiebach for the form of
finite generalised diffeomorphisms is shown to hold. Transition functions on
overlaps are defined. Triple overlaps are trivial concerning their action on
coordinates, but non-trivial on fields, including the generalised metric. A
generalised manifold is an ordinary manifold, but the generalised metric on the
manifold carries a gerbe structure. We show how the abelian behaviour of the
gerbe is embedded in the non-abelian T-duality group. We also comment on
possibilities and difficulties in the U-duality setting.Comment: 20 pp. v3: refs. added, discussion added on limitations of formalis
Selfdual Spin 2 Theory in a 2+1 Dimensional Constant Curvature Space-Time
The Lagrangian constraint analysis of the selfdual massive spin 2 theory in a
2+1 dimensional flat space-time and its extension to a curved one, are
performed. Demanding consistence of degrees of freedom in the model with
gravitational interaction, gives rise to physical restrictions on non minimal
coupling terms and background. Finally, a constant curvature scenario is
explored, showing the existence of forbidden mass values. Causality in these
spaces is discussed. Aspects related with the construction of the reduced
action and the one-particle exchange amplitude, are noted.Comment: 20 pages, references added, little modifications performe
T-duality in the weakly curved background
We consider the closed string propagating in the weakly curved background
which consists of constant metric and Kalb-Ramond field with infinitesimally
small coordinate dependent part. We propose the procedure for constructing the
T-dual theory, performing T-duality transformations along coordinates on which
the Kalb-Ramond field depends. The obtained theory is defined in the
non-geometric double space, described by the Lagrange multiplier and
its -dual . We apply the proposed T-duality procedure to the
T-dual theory and obtain the initial one. We discuss the standard relations
between T-dual theories that the equations of motion and momenta modes of one
theory are the Bianchi identities and the winding modes of the other
Towards an M5-Brane Model II:Metric String Structures
In this paper, we develop the mathematical formulation of metric string
structures. These play a crucial role in the formulation of certain
six-dimensional superconformal field theories and we believe that they also
underlie potential future formulations of the (2,0)-theory. We show that the
connections on non-abelian gerbes usually introduced in the literature are
problematic in that they are locally gauge equivalent to connections on abelian
gerbes. Connections on string structures form an exception and we introduce the
general concept of an adjusted Weil algebra leading to potentially interacting
connections on higher principal bundles. Considering a special case, we derive
the metric extension of string structures and the corresponding adjusted Weil
algebra. The latter lead to connections that were previously constructed by
hand in the context of gauged supergravities. We also explain how the Leibniz
algebras induced by an embedding tensor in gauged supergravities fit into our
picture.Comment: v2: 70 pages, presentation improved, typos fixed, published versio
A Complete Classification of Higher Derivative Gravity in 3D and Criticality in 4D
We study the condition that the theory is unitary and stable in
three-dimensional gravity with most general quadratic curvature,
Lorentz-Chern-Simons and cosmological terms. We provide the complete
classification of the unitary theories around flat Minkowski and (anti-)de
Sitter spacetimes. The analysis is performed by examining the quadratic
fluctuations around these classical vacua. We also discuss how to understand
critical condition for four-dimensional theories at the Lagrangian level.Comment: 20 pages, v2: minor corrections, refs. added, v3: logic modified, v4:
typos correcte
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