Description
String theory provides us with UV-finite amplitudes of quantum gravity at every
order in perturbation theory.
However, explicit computations become quickly very complicated, to the point that their
evaluation have been possible only in the low- and high- energy expansion. Essentially no
results are known at intermediate values of \alpha’.
In this talk, I will present a novel technique to evaluate one-loop amplitudes at finite
\alpha’, which also implements the i \epsilon prescription in string theory, and illustrate new
computational windows it opens.
Based on https://arxiv.org/abs/2501.13827, https://arxiv.org/pdf/2507.22105 and https://
arxiv.org/pdf/2601.09707.