In this work we propose an exact microscopic description of maximally symmetric branes in a Euclidean AdS 3 background. As shown by Bachas and Petropoulos, the most important such branes are localized along a Euclidean AdS 2 ⊂ AdS 3. We provide explicit formulas for the coupling of closed strings to such branes (boundary states) and for the spectral density of open strings. The latter is computed in two different ways first in terms of the open string reflection amplitude and then also from the… CONTINUE READING