The Thermal Bath of de Sitter from Holography

TL;DR

This paper explores the holographic dual of de Sitter space, revealing how thermal properties of the boundary field theory emerge from cosmological expansion without black holes, affecting meson stability and correlation functions.

Contribution

It demonstrates how de Sitter holography encodes thermal behavior through cosmological expansion instead of black holes, analyzing various observables like entanglement entropy and meson energies.

Findings

Entanglement entropy and two-point functions are temperature-independent due to conformal symmetry.

Maximum stable distance and spin for mesons are identified, indicating bound state instability.

Thermal properties in the absence of black holes are attributed to the cosmological expansion of de Sitter space.

Abstract

We consider the AdS/dS CFT correspondence and study the nature of the thermal bath of the de Sitter field theory using holography. Unlike the temperature of a thermal field theory in flat spacetime, the temperature of a superconformal field theory on de Sitter space is an integral part of the theory and leaves intact the conformal symmetry and supersymmetry. In the dual AdS side, there is no black hole. Instead we have cosmological expansion of the de Sitter factor. We consider a number of different observables, such as the entanglement entropy, two point correlation function, Wilson loops corresponding to static and spinning mesons in the field theory, and study their thermal properties using holography. The former two quantities have trivial temperature dependence due to conformal symmetry. We compute the energy of the quark anti-quark bound state for a static meson, as well as the energy and the angular momentum for a spinning meson. We find that there is a maximum distance, as well as a maximum spin for the latter case, beyond which the bound state become unstable. The temperature behavior of the physical quantities in these meson systems are similar to that of the usual thermal field theory with holographic black hole dual. With these examples, we show clearly how the field theory observables get their thermal properties from the bulk despite the absence of a black hole, with the role of the black hole horizon played by the cosmological expansion of the de Sitter factor of the AdS metric.