Speaker
Sitender Kashyap
Description
Scattering amplitudes in string theory describe how strings interact, but even the simplest cases can be subtle in modern formulations. In this talk, I will revisit the two-point function for closed strings in the pure spinor approach, where a naïve extension of open-string methods fails.
We will show how this issue can be resolved by carefully implementing BRST symmetry, leading to a consistent and essentially unique prescription based on an unconventional choice of variables. This completes the picture for this class of amplitudes and clarifies an important aspect of the formalism.