A brane-bulk matter relation for a purely conical codimension-2 brane world

We study gravity on an infinitely thin codimension-2 brane world, with purely conical singularities and in the presence of an induced gravity term on the brane. We show that in this approximation, the energy - momentum tensor of the bulk is strongly related to the energy - momentum tensor of the brane and thus the gravity dynamics on the brane is induced by the bulk content. This is in contrast with the case for the gravity dynamics on a codimension- 1 brane. We show how this strong result is relaxed after including a Gauss - Bonnet term in the bulk.