Dual of the Identity operator (AdS/CFT)

Question

We know that in a CFT the spectrum of gauge invariant operators must contain an Identity operator (for the operator algebra to close). For those CFTs that admit a holographic dual what does the Identity operator correspond to in the bulk?

This post imported from StackExchange Physics at 2015-09-30 17:12 (UTC), posted by SE-user Orbifold

Comments

Shouldn't it also correspond to the identity (field) operator? If you insert the identity operator in a correlator, nothing changes.