Non‐geometric fluxes in supergravity and double field theory

In this paper we propose ten‐dimensional realizations of the non‐geometric fluxes Q and R . In particular, they appear in the NSNS Lagrangian after performing a field redefinition that takes the form of a T‐duality transformation. Double field theory simplifies the computation of the field redefinition significantly, and also completes the higher‐dimensional picture by providing a geometrical role for the non‐geometric fluxes once the winding derivatives are taken into account. The relation to four‐dimensional gauged supergravities, together with the global obstructions of non‐geometry, are discussed.