Aspects of Quantum Gravity in de Sitter Spaces

TL;DR

This paper reviews recent theoretical approaches to understanding quantum gravity in de Sitter spaces, focusing on holographic dualities, no-go theorems, and the thermal properties of these cosmological models.

Contribution

It synthesizes various proposals and results on quantum gravity in de Sitter spaces, highlighting how holography and string theory challenges are addressed.

Findings

Holographic correspondences between de Sitter space and conformal field theories.

Circumventing no-go theorems for embedding de Sitter in string theory.

Insights into the thermal nature of de Sitter space.

Abstract

In these lectures we give a review of recent attempts to understand quantum gravity on de Sitter spaces. In particular, we discuss the holographic correspondence between de Sitter gravity and conformal field theories proposed by Hull and by Strominger, and how this may be reconciled with the finite-dimensional Hilbert space proposal by Banks and Fischler. Furthermore we review the no-go theorems that forbid an embedding of de Sitter spaces in string theory, and discuss how they can be circumvented. Finally, some curious issues concerning the thermal nature of de Sitter space are elucidated.