Four String Amplitudes for the Generalized Protostring

Abstract

We specialize the $N$ string scattering amplitudes for the generalized protostring to $N=4$. This allows for a much more detailed and explicit study of their basic physical and mathematical properties, such as singularity structure and high energy behavior. Since this class of models does not enjoy full Poincar\'e invariance, the high energy behavior depends on the Lorentz frame. The relative simplicity of the four string amplitudes allows a direct understanding of the complications due to this non-covariance.