Double metric, generalized metric, and -deformed double field theory

Citation Hohm, Olaf, and Barton Zwiebach. "Double metric, generalized metric, and-deformed double field theory. Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. We relate the unconstrained " double metric " of the " α 0-geometry " formulation of double field theory to the constrained generalized metric encoding the spacetime metric and b-field. This is achieved by integrating out auxiliary field components of the double metric in an iterative procedure that induces an infinite number of higher-derivative corrections. As an application, we prove that, to first order in α 0 and to all orders in fields, the deformed gauge transformations are Green-Schwarz–deformed diffeomorphisms. We also prove that to first order in α 0 the spacetime action encodes precisely the Green-Schwarz deformation with Chern-Simons forms based on the torsionless gravitational connection. This seems to be in tension with suggestions in the literature that T-duality requires a torsionful connection, but we explain that these assertions are ambiguous since actions that use different connections are related by field redefinitions.