Localized modes at a D-brane--O-plane intersection and heterotic Alice strings

TL;DR

This paper investigates localized chiral fermion zero-modes at D-brane and O-plane intersections, connecting string dualities, anomaly cancellation, and F-theory to heterotic string theory and holographic duals.

Contribution

It demonstrates the existence of localized chiral zero-modes in a D3-D7-O7 system using anomaly considerations and index theory, linking to heterotic strings and AdS/CFT correspondence.

Findings

Chiral zero-modes are localized near O7-planes.

The system relates to F-theory on K3 and heterotic matrix strings.

An AdS3 dual of the heterotic matrix string CFT is identified.

Abstract

We study a system of $N_c$ $D3$-branes intersecting $D7$-branes and $O7$-planes in 1+1-dimensions. We use anomaly cancellation and string dualities to argue that there must be chiral fermion zero-modes on the $D3$-branes which are localized near the $O7$-planes. Away from the orientifold limit we verify this by using index theory as well as explicit construction of the zero-modes. This system is related to F-theory on K3 and heterotic matrix string theory, and the heterotic strings are related to Alice string defects in $\mathcal{N}=4$ Super-Yang-Mills. In the limit of large $N_c$ we find an $AdS_3$ dual of the heterotic matrix string CFT.