To quote Lee Smolin:
"It makes no sense to talk about things 'outside the Universe'. The Universe is defined as being all that there is."
Although I expect that's what you mean by 'the Bulk'. How can something outside our lightcone affect us?
( Cap'n Tallbeard, Wed 28 Nov 2007, 16:25, archived)

The bulk is a prediction of some Brane theories.
Those theories though like all scientific things only operate in their specified domain, and make no prediction of what happens outside of that domain.
( Sygiinu, Wed 28 Nov 2007, 16:28, archived)