http://inspirehep.net/record/499969/files/arXiv:hep-th_9905111.pdf

Large N Field Theories, String Theory and Gravity

Unity of superstring dualities

There is strong evidence that the area of any surface limits the information content of adjacent spacetime regions, at $1.4\ifmmode\times\else\texttimes\fi{}{10}^{69}$ bits per square meter. This article reviews the developments that have led to the recognition of this entropy bound, placing special emphasis on the quantum properties of black holes. The construction of light sheets, which associate relevant spacetime regions to any given surface, is discussed in detail. This article explains how the bound is tested, and its validity is demonstrated in a wide range of examples. A universal relation between geometry and information is thus uncovered. It has yet to be explained. The holographic principle asserts that its origin must lie in the number of fundamental degrees of freedom involved in a unified description of spacetime and matter. It must be manifest in an underlying quantum theory of gravity. This article surveys some successes and challenges in implementing the holographic principle.

The Holographic principle

A holographic duality is proposed relating quantum gravity on dSD (D-dimensional de Sitter space) to conformal field theory on a single SD−1 ((D-1)-sphere), in which bulk de Sitter correlators with points on the boundary are related to CFT correlators on the sphere, and points on + (the future boundary of dSD) are mapped to the antipodal points on SD−1 relative to those on − For the case of dS3, which is analyzed in some detail, the central charge of the CFT2 is computed in an analysis of the asymptotic symmetry group at ± This dS/CFT proposal is supported by the computation of correlation functions of a massive scalar field In general the dual CFT may be non-unitary and (if for example there are sufficently massive stable scalars) contain complex conformal weights We also consider the physical region − of dS3 corresponding to the causal past of a timelike observer, whose holographic dual lives on a plane rather than a sphere − can be foliated by asymptotically flat spacelike slices Time evolution along these slices is generated by L0+0, and is dual to scale transformations in the boundary CFT2

https://iopscience.iop.org/article/10.1088/1126-6708/2001/10/034/pdf

A. Achucarro

Papers

A Chern-Simons Action for Three-Dimensional anti-De Sitter Supergravity Theories

Super p-Branes