Dynamical Behavior of dilaton in de Sitter space

TL;DR

This paper investigates the behavior of the dilaton field in three-dimensional Kerr-de Sitter space, analyzing its stability, interactions, and absorption properties near the cosmological horizon.

Contribution

It provides a detailed perturbation analysis, introduces a gauge to decouple the dilaton, and explores the dilaton's stability and absorption cross section in de Sitter space.

Findings

Dilaton mixes with other fields near the horizon.

Decoupling gauge reveals the dilaton as a tachyonic mode.

Computed the dilaton absorption cross section.

Abstract

We study the dynamical behavior of the dilaton in the background of three-dimensional Kerr-de Sitter space which is inspired from the low-energy string effective action. The perturbation analysis around the cosmological horizon of Kerr-de Sitter space reveals a mixing between the dilaton and other fields. Introducing a gauge (dilaton gauge), we can disentangle this mixing completely and obtain one decoupled dilaton equation. However it turns out that this belongs to the tachyon. The stability of de Sitter solution with J=0 is discussed. Finally we compute the dilaton absorption cross section to extract information on the cosmological horizon of de Sitter space.