Description
I will describe new aspects of KLT factorization for relativistic string theory where the strings carry both momentum and winding. This gives rise to an interesting D-brane configuration in spacetime when we consider the open string amplitudes. I will then present a zero Regge slope limit of the KLT relations between winding string amplitudes. Such a limit of string theory requires a critically tuned Kalb-Ramond field in the compact directions, and results in the D-branes carrying an electric potential. Finally I will present the one loop open string amplitudes which extends the work of Gomis and Ooguri for closed strings.
