Anomalous couplings for D-branes and O-planes

TL;DR

This paper investigates the anomalous Wess-Zumino couplings of D-branes and O-planes, deriving their forms from string theory calculations and revealing their dependence on curvature and characteristic classes.

Contribution

It provides a direct string computation method to derive anomalous couplings for D-branes and O-planes, including gravitational couplings involving the Hirzebruch polynomial.

Findings

O-planes have gravitational anomalous couplings involving the Hirzebruch polynomial L.

The couplings depend precisely on the curvature of tangent and normal bundles.

The derivation confirms the form of anomalous couplings from string amplitude factorization.

Abstract

We study anomalous Wess-Zumino couplings of D-branes and O-planes in a general background and derive them from a direct string computation by factorizing in the RR channel various one-loop amplitudes. In particular, we find that Op-planes present gravitational anomalous couplings involving the Hirzebruch polynomial L, similarly to the roof genus A encoding Dp-brane anomalous couplings. We determine, in each case, the precise dependence of these couplings on the curvature of the tangent and normal bundles.