Strings and the Holographic Description of Asymptotically de Sitter Spaces

TL;DR

This paper explores the holographic description of asymptotically de Sitter spaces using string theory, showing that boundary theories correspond to strings at the stretched horizon with a modified Cardy--Verlinde formula.

Contribution

It demonstrates that the Cardy--Verlinde formula describes a string at the stretched horizon with rescaled tension, linking boundary theories to horizon strings in de Sitter space.

Findings

The boundary entropy matches the string at the stretched horizon.

The temperature corresponds to the rescaled Hagedorn temperature.

The two descriptions are related by gravitational redshift and energy shift.

Abstract

Asymptotically de Sitter spaces can be described by Euclidean boundary theories with entropies given by the modified Cardy--Verlinde formula. We show that the Cardy--Verlinde formula describes a string with a rescaled tension which in fact is a string at the stretched cosmological horizon as seen from the boundary. The temperature of the boundary theory is the rescaled Hagedorn temperature of the string. Our results agree with an alternative description of asymptotically de Sitter spaces in terms of strings on the stretched horizon. The relation between the two descriptions is given by the large gravitational redshift between the boundary and the stretched horizon and a shift in energy.