In double field theory, the equation of motion for a point particle in the background field is considered. We find that the motion is described by a geodesic flow in the doubled geometry. Inspired by the analysis on the particle motion, we consider a modified model of quantum string cosmology, which includes two scale factors.

• Received 5 October 2011

DOI:https://doi.org/10.1103/PhysRevD.84.124049