  We relate two formulations of the recently constructed double field theory to
a frame-like geometrical formalism developed by Siegel. A self-contained
presentation of this formalism is given, including a discussion of the
constraints and its solutions, and of the resulting Riemann tensor, Ricci
tensor and curvature scalar. This curvature scalar can be used to define an
action, and it is shown that this action is equivalent to that of double field
theory.

High Energy Physics - Theory