A Heat Shield for de Sitter space

TL;DR

This paper explores how a perfectly reflecting box in 1+1 dimensional de Sitter space creates a quiescent region with reduced temperature and energy, affecting thermal effects and entropy exchange near the horizon.

Contribution

It introduces a quantum vacuum state in de Sitter space with a reflecting boundary, revealing a novel 'quiescent oasis' with implications for thermodynamics and horizon physics.

Findings

Detector inside the box registers zero response.

The box's temperature is below the de Sitter horizon temperature.

Total energy in the box is less than the same volume in thermal equilibrium.

Abstract

We investigate a quantum vacuum state for $1 + 1$ dimensional de Sitter space, corresponding to a region within a perfectly reflecting symmetric box of fixed physical size. We find that a particle detector inside the box registers zero response, implying that the walls of the box screen out the thermal effects of the de Sitter horizon. The box thus creates a `quiescent oasis' with a temperature below the de Sitter horizon temperature, an unexpected feature that opens the way to an analysis of heat and entropy exchange between the box and the horizon in the context of the generalized second law of thermodynamics. We also calculate the stress-energy-momentum tensor of the region within the box, showing that the total energy in the box is less than the same volume of de Sitter space in the presence of thermal fluctuations.