Anomalies and inflow on D-branes and O-planes

TL;DR

This paper derives the anomaly structure for fields on D-branes and O-planes and demonstrates how their couplings to RR forms cancel these anomalies via inflow, enabling local anomaly cancellation in orientifold models.

Contribution

It provides a general derivation of anomalies and their cancellation mechanisms for D-branes and O-planes using path-integral and index theorem methods.

Findings

Anomaly expressions for chiral spinors and self-dual tensors on D-branes/O-planes

Matching of anomalous couplings to RR forms for anomaly cancellation

Application to local anomaly cancellation in orientifold models

Abstract

We derive the general form of the anomaly for chiral spinors and self-dual antisymmetric tensors living on D-brane and O-plane interesections, using both path-integral and index theorem methods. We then show that the anomalous couplings to RR forms of D-branes and O-planes in a general background are precisely those required to cancel these anomalies through the inflow mechanism. This allows, for instance, for local anomaly cancellation in generic orientifold models, the relevant Green-Schwarz term being given by the sum of the anomalous couplings of all the D-branes and O-planes in the model.