F-theory at order α′3

We study the effective physics of F-theory at order alpha'(3) in derivative expansion. We show that the ten-dimensional type IIB eight-derivative couplings involving the graviton and the axio-dilaton naturally descend from pure gravity in twelve dimensions. Upon compactification on elliptically fibered Calabi-Yau fourfolds, the non-trivial vacuum profile for the axio-dilaton leads to a new, genuinely N = 1, alpha'(3) correction to the four-dimensional effective action.