Thermal aspects in curved metrics

TL;DR

This paper compares semi-classical and quantum field-theoretical methods for analyzing thermal phenomena, like Hawking radiation and Unruh effect, in curved spacetimes, highlighting their applications and differences.

Contribution

It introduces and compares the tunnelling method and Unruh-DeWitt detector approach for calculating thermal features in curved spacetimes.

Findings

Tunnelling method provides straightforward horizon temperature calculations.

Unruh-DeWitt detector offers more precise transition rate analysis.

Both methods are applicable to various curved spacetime scenarios.

Abstract

In this paper we describe two approaches that allow to calculate some thermal features as perceived by different observers in curved spacetimes: the tunnelling method and the Unruh-DeWitt detector. The tunnelling phenomenon is a semi-classical approach to the issue of Hawking radiation and allows a straightforward calculation of the horizon temperature in a plethora of scenarios; the Unruh-DeWitt model relies instead on a quantum field-theoretical approach and (whenever possible) gives a more exact answer in terms of transition rates between energy levels of an idealized detector.