Boundary states in the Nappi-Witten model

TL;DR

This paper classifies and constructs boundary states for D-branes in the Nappi-Witten model, linking classical geometry with quantum boundary state descriptions through conformal bootstrap calculations.

Contribution

It provides a classification of D-branes via conjugacy classes and explicitly constructs boundary states that match classical geometries in the quantum regime.

Findings

Boundary states reproduce classical D-brane geometries

One point functions satisfy conformal bootstrap constraints

Quantum description aligns with classical D-brane configurations

Abstract

We investigate D-branes in the Nappi-Witten model. Classically symmetric D-branes are classified by the (twisted) conjugacy classes of the Nappi-Witten group, which specify the geometry of the corresponding D-branes. Quantum description of the D-branes is given by boundary states, and we need one point functions of closed strings to construct the boundary states. We compute the one point functions solving conformal bootstrap constraints, and check that the classical limit of the boundary states reproduces the geometry of D-branes.