Ramond-Ramond field strength couplings on D-branes

TL;DR

This paper derives specific couplings between Ramond-Ramond and NSNS fields on D-branes by analyzing string scattering amplitudes, ensuring consistency with T-duality transformations and clarifying the form of RR field strengths.

Contribution

It provides explicit disk-level couplings involving derivatives of RR field strengths and fixes ambiguities using T-duality, advancing understanding of D-brane effective actions.

Findings

Couplings involve derivatives of RR field strengths F^{(p)}, F^{(p+2)}, F^{(p+4)}.

On-shell ambiguities are fixed by linear T-duality.

RR field strength is confirmed to be { m{f{ extcal F}}}=d{ m{f{ extcal C}}} with { m{f{ extcal C}}}=e^{B}C.

Abstract

By examining in details the disk level S-matrix element of one massless RR and one NSNS states at order O(\alpha'^2), we find the coupling of one RR and one NSNS fields on the world volume of a D$_p$-brane. The non-zero couplings involve the first derivative of the RR field strengths F^{(p)}, F^{(p+2)} and F^{(p+4)}. We then fix the on-shell ambiguity of the couplings by requiring consistency with the linear T-duality transformations. Moreover, consistency with the non-linear T-duality requires that the RR field strength in the above couplings to be {\cal F}=d{\cal C} where {\cal C}=e^{B}C.