Classical p-branes from boundary state

TL;DR

The paper establishes a direct link between D$p$-brane boundary states and their classical low-energy supergravity descriptions by projecting the BRST-invariant boundary state onto massless closed-string states. Using NS-NS and RR sector analyses, and employing an asymmetric RR picture as well as delocalized bound-state constructions, the authors reproduce the brane tension $T_p$, RR charge $\mu_p$, and the correct long-distance field profiles $h_{\mu\nu}$, $\varphi$, $B_{\mu\nu}$ and RR potentials, verifying consistency with classical p-brane solutions in ten dimensions. The work extends to bound states, showing that rotated and T-dualized boundary states generate the expected multiple RR fields in agreement with Myers, thereby broadening the boundary-state–classical-solution correspondence. Overall, the approach provides a compact, string-level derivation linking boundary state data to spacetime p-brane backgrounds and their bound-state generalizations, strengthening the connection between worldsheet BRST structure and spacetime supergravity solutions.

Abstract

We show that the boundary state description of a Dp-brane is strictly related to the corresponding classical solution of the low-energy string effective action. By projecting the boundary state on the massless states of the closed string we obtain the tension, the R-R charge and the large distance behavior of the classical solution. We discuss both the case of a single D-brane and that of bound states of two D-branes. We also show that in the R-R sector the boundary state, written in a picture which treats asymmetrically the left and right components, directly yields the R-R gauge potentials.