88 research outputs found
7-dimensional Consistent Truncations using Exceptional Field Theory
We show how to construct seven-dimensional half-maximally supersymmetric
consistent truncations of 11-/10-dimensional SUGRA using
exceptional field theory. Such truncations are defined on generalised
-structure manifolds and give rise to seven-dimensional
half-maximal gauged supergravities coupled to vector multiplets and thus
with scalar coset space . The consistency conditions
for the truncation can be written in terms of the generalised Lie derivative
and take a simple geometric form. We show that after imposing certain "doublet"
and "closure" conditions, the embedding tensor of the gauged supergravity is
given by the intrinsic torsion of generalised -connections and
automatically satisfies the linear constraint of seven-dimensional half-maximal
gauged supergravities, as well as the quadratic constraint when the section
condition is satisfied.Comment: 46 pages; v2: minor changes, published versio
Non-geometric Kaluza-Klein monopoles and magnetic duals of M-theory R-flux backgrounds
We introduce a magnetic analogue of the seven-dimensional nonassociative
octonionic R-flux algebra that describes the phase space of M2-branes in
four-dimensional locally non-geometric M-theory backgrounds. We show that these
two algebras are related by a Spin(7) automorphism of the 3-algebra that
provides a covariant description of the eight-dimensional M-theory phase space.
We argue that this algebra also underlies the phase space of electrons probing
a smeared magnetic monopole in quantum gravity by showing that upon appropriate
contractions, the algebra reduces to the noncommutative algebra of a spin foam
model of three-dimensional quantum gravity, or to the nonassociative algebra of
electrons in a background of uniform magnetic charge. We realise this set-up in
M-theory as M-waves probing a delocalised Kaluza-Klein monopole, and show that
this system also has a seven-dimensional phase space. We suggest that the
smeared Kaluza-Klein monopole is non-geometric because it cannot be described
by a local metric. This is the magnetic analogue of the local non-geometry of
the R-flux background and arises because the smeared Kaluza-Klein monopole is
described by a U(1)-gerbe rather than a U(1)-fibration.Comment: 19 pages, 2 figures; v2: dimensionful factors corrected throughout,
exposition improved; Final version to be published in JHE
The Information Metric on the moduli space of instantons with global symmetries
In this note we revisit Hitchin's prescription \cite{Hitchin} of the Fisher
metric as a natural measure on the moduli space of instantons that encodes the
space-time symmetries of a classical field theory. Motivated by the idea of the
moduli space of supersymmetric instantons as an emergent space in the sense of
the gauge/gravity duality, we extend the prescription to encode also global
symmetries of the underlying theory. We exemplify our construction with the
instanton solution of the sigma model on .Comment: 5 pages, no figures, sorr
Open-String Non-Associativity in an R-flux Background
We derive the commutation relations for open-string coordinates on D-branes
in non-geometric background spaces. Starting from D0-branes on a
three-dimensional torus with H-flux, we show that open strings with end points
on D3-branes in a three-dimensional R-flux background exhibit a non-associative
phase-space algebra, which is similar to the non-associative R-flux algebra of
closed strings. Therefore, the effective open-string gauge theory on the
D3-branes is expected to be a non-associative gauge theory. We also point out
differences between the non-associative phase space structure of open and
closed strings in non-geometric backgrounds, which are related to the different
structure of the world-sheet commutators of open and closed strings.Comment: 29 pages; v2: added section 3.5, minor changes; v3: published
version, clarifications added in sections 3 and 4, added appendix B.
A geometric formulation of exceptional field theory
We formulate the full bosonic SL(5) exceptional field theory in a
coordinate-invariant manner. Thereby we interpret the 10-dimensional extended
space as a manifold with -structure. We show
that the algebra of generalised diffeomorphisms closes subject to a set of
closure constraints which are reminiscent of the quadratic and linear
constraints of maximal seven-dimensional gauged supergravities, as well as the
section condition. We construct an action for the full bosonic SL(5)
exceptional field theory, even when the
-structure is not locally flat.Comment: 46 page
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