Gauged double field theory, current algebras and heterotic sigma models

We study the O(D, D + n) generalized metric and the gauge symmetries in the gauged double field theory (DFT) in view of current algebras and sigma models. We show that the O(D, D + n) generalized metric in the gauged DFT is consistent with the heterotic sigma models at the leading order in the alpha '-corrections. We then study the non-Abelian gauge symmetries and current algebras of heterotic string theories. We show that the algebras exhibit the correct diffeomorphism, the B-field gauge transformations of the background fields together with the non-Abelian gauge transformations possibly with the appropriate local Lorentz transformations.