Four-Derivative Brane Couplings from String Amplitudes

الأصل · EN

We evaluate the string theory disc amplitude of one Ramond-Ramond field C(p-3) and two Neveu-Schwarz B-fields in the presence of a single Dp-brane in type II string theory. From this amplitude we extract the four-derivative (or equivalently order (alpha')²) part of the Dp-brane action involving these fields. We show that the new couplings are invariant under R-R and NS-NS gauge transformations and compatible with linear T-duality.