pp waves and holography

We consider aspects of holography in the pp-wave limit of AdS₅ × S⁵. This geometry contains two R⁴'s, one obtained from AdS₅ directions, and the other from the S⁵. We argue that the holographic direction in the pp-wave background can be taken to be r, the radial direction in the first R⁴. Normalizable modes correspond to states, and non-normalizable modes correspond to deformations of the boundary theory. In the strict pp-wave limit, there are additional non-normalizable modes in the second R⁴, which have no apparent super-Yang-Mills interpretation. We outline the procedure for calculating correlation functions holographically.