Semiclassical bosonic D-brane boundary states in curved spacetime

TL;DR

This paper presents a perturbative method to compute semiclassical bosonic D-brane boundary states in arbitrary curved spacetimes, including AdS, considering both metric and Kalb-Ramond fields.

Contribution

It introduces a simple perturbative approach to calculate D-brane boundary states in general curved backgrounds with exact treatment of the metric and antisymmetric fields.

Findings

First-order perturbation yields D-brane coherent states in AdS spacetime.

Method applicable to arbitrary curved spacetimes with combined metric and Kalb-Ramond fields.

Conditions identified for boundary projectors to produce coherent states.

Abstract

We give a simple method to calculate the semiclassical $D$-brane boundary states of the bosonic string propagating in an arbitrary curved spacetime in a perturbative approach in which the metric $g_{AB}$ and the constant antisymmetric Kalb-Ramond field $b_{AB}$ form the general background which is treated exactly. As an important particular case, it is shown that at the first order perturbation theory there are $D$-brane coherent states in the $d$-dimensional {\em AdS} spacetime if certain conditions are fulfilled by the boundary projectors.