Towards string loop corrections in Calabi-Yau orientifold compactifications

Computation of string loop corrections to the effective action has been one of the main challenges in string phenomenology. One major complication for such computations is that the string loop corrections are sensitive to the spectrum of strings probing Calabi-Yau orientifolds, which is practically inaccessible. In this talk, I will claim that some terms in the string one loop corrections to the Kahler potential are computed by more computable crude details of the string spectrum. This result may pave a way to explicit computations of the string loop corrections in generic Calabi-Yau orientifold compactifications.