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.
Categories: hep-th