Ramond-Ramond couplings of non-BPS D-branes
Marco Billo', Ben Craps, Frederik Roose
TL;DR
The paper addresses how non-BPS type II D-branes couple to Ramond-Ramond potentials and shows that tachyon condensation induces the Wess-Zumino action of BPS D-branes. It proposes a universal RR coupling for non-BPS D$p$-branes: $S'_{WZ}=a\int_{p+1} C\wedge d\mathrm{Tr} T\, e^{2\pi\alpha' F+B} \wedge \sqrt{\hat{A}(R_T)/\hat{A}(R_N)}$. Through vortex/monopole tachyon configurations on stacks of unstable D$p$-branes, the authors derive RR couplings for $D(p-1)$ and $D(p-3)$ branes and verify RR charge ratios such as $4\pi^2\alpha'$. The authors confirm the couplings by disc amplitudes with tachyon and RR vertex operators, using the doubling trick and showing consistency with the BPS WZ action.
Abstract
We study how non-BPS type II D-branes couple to R-R potentials. Upon tachyon condensation the couplings we find give rise to the Wess-Zumino action of BPS D-branes.