40 research outputs found
Exceptional field theory:
We construct Exceptional Field Theory for the group based on the
extended (6+16)-dimensional spacetime, which after reduction gives the maximal
supergravity. We present both a true action and a duality-invariant
pseudo-action formulations. All the fields of the theory depend on the complete
extended spacetime. The U-duality group is made a geometric symmetry
of the theory by virtue of introducing the generalised Lie derivative that
incorporates a local duality transformation. Tensor hierarchy appears as a
natural consequence of the algebra of generalised Lie derivatives that are
viewed as gauge transformations. Upon truncating different subsets of the extra
coordinates, maximal supergravities in and (type IIB) can be
recovered from this theory.Comment: 33 pages + Appendi
Non-geometric branes are DFT monopoles
The double field theory monopole solution by Berman and Rudolph is shown to
reproduce non-geometric backgrounds with non-vanishing Q- and R-flux upon an
appropriate choice of physical and dual coordinates. The obtained backgrounds
depend non-trivially on dual coordinates and have only trivial monodromies.
Upon smearing the solutions along the dual coordinates one reproduces the known
solution for the Q-brane and co-dimension 1 solution for the R-brane.
The T-duality invariant magnetic charge is explicitly calculated for all these
backgrounds and is found to be equal to the magnetic charge of (unsmeared)
NS5-brane.Comment: 26 pages and appendi
Non-abelian U-duality at work
Non-abelian U-duality originates from the construction of exceptional
Drinfel'd algebra (EDA), which extends the constriction of the classical
Drinfel'd double. This symmetry is a natural extension of Poisson--Lie
T-duality and is believed to be a symmetry of Type II string/M-theory or their
low-energy effective theories. In this paper, we consider non-abelian
U-dualities of 11- or 10-dimensional backgrounds starting with
EDA with with vanishing trombone gauging. The
latter guarantees that all dual backgrounds satisfy the standard supergravity
equations of motion. In particular, when the duality includes a timelike
T-duality, we obtain solutions of M-theory or Type II background
equations, as expected. Also starting with coboundary EDA's we provide examples
of generalised Yang--Baxter deformations of M-theory and Type IIB backgrounds.
The obtained results provide explicit examples when non-abelian U-duality works
well as a solution generating transformation.Comment: 38