Exotic branes in Double Field Theory

Abstract

Abstract. The non-geometric Q-and R-monopole are shown to be a particular case of the DFT-monopole solution. The notion of magnetic charge for the solutions is defined and shown to be equal to the magnetic charge of the NS5-brane solution. This is a talk presented by the author at the conference QUARKS'16 in St.-Petersburg. T-duality and Double Field TheoryIt is known that string theory respects a hidden symmetry, called T-duality, on the quantum perturbative level. The most intuitive way of understanding the action of this symmetry is consider swapping of momentum and winding modes of a closed string on a d-torus T d . In this case the T-duality symmetry group is O (d, d). It has long been conjectured that these symmetries must carry some geometric meaning which would allow to define them on non-toroidal backgrounds.The Siegel [2] that left and right movers on the string worldsheet should be considered independently and generalizes the construction of generalized geometry by Hitchin, Cavalcanti and Gualtiery (see [3] for review and further links). The pioneering works in this direction were [4,5] by Hull, Hohm and Zwiebach who presented the background independent duality covariant formulation of the action of DFT in terms of the so-called generalized metric H MN . Soon after the same was done for the U-duality groups in [6][7][8] for the internal sector only, and in [9][10][11][12] for the full theory including p-forms. Supersymmetric extension and inclusion of fermions has been presented in [13,14] for DFT and in [15,16] for EFT.The idea behind Double Field Theory is that one doubles the space-time by adding dual coordinatesx μ corresponding to winding modes of closed strings. The resulting space-time (better to say 'space' to avoid issues with imaginary time) is parametrized by (d + d) coordinates X M = {x μ ,x μ }. The fields of the NS-NS sector, i.e. the metric, the B-field, and the dilaton, combine into the generalized metric H MN that transforms covariantly under O (d, d) transformations O and depends on all the coordinates

Exotic branes in Exceptional Field Theory: the SL(5) duality group

“…Instead, as shown in [46,51], it solves the equations of motion of DFT. In the works [52,53] the T-duality chain has been investigated further and the backgrounds describing the so-called exotic Q-and R-branes have been obtained. When smeared along all the dual coordinates these correspond to the 5 2 2 and 5 3 2 branes of Shigemori and de Boer.…”

Reductions of exceptional field theories

“…We shall not describe such objects in any more detail but refer the reader to [33,35,36] for a description of such objects within string theory. Additionally, there is a growing body of work describing such objects including explicit constructions of such solutions in ExFT, worldvolume actions for exotic 5-branes and the classification of the mixed-symmetry potentials that they couple to [37][38][39][40][41][42][43][44][45][46][47][48].…”