Holography in the Penrose limit of AdS space

TL;DR

This paper explores the holographic structure emerging in the Penrose limit of AdS space, revealing a gauge-fixed 'holographic screen' where conformal symmetry encodes CFT information despite the absence of a traditional holographic principle.

Contribution

It introduces a novel gauge-fixing approach to define a holographic screen in flat space derived from AdS, connecting Poincare and conformal algebras in this limit.

Findings

Holographic screen encodes CFT data in flat space

Gauge fixing relates Poincare and conformal algebras

Penrose limit leads to a conformal structure on the screen

Abstract

We discuss the Penrose limit of pure AdS space, which is flat Minkowski space. Even though there is no holographic principle, we construct a ``holographic screen'' on which information on the corresponding CFT is encoded. The screen is obtained as a gauge-fixing condition upon restricting the Hilbert space to the states that are annihilated by the generator of scale transformations. This constraint leads to Dirac brackets which turn the Poincare algebra into the algebra of the conformal group on the ``holographic screen.''