Superluminal dispersion relations and the Unruh effect

TL;DR

This paper investigates how superluminal dispersion relations, relevant in quantum gravity, modify the Unruh effect, showing that such modifications cause corrections to the expected thermal spectrum that diminish with higher threshold momenta.

Contribution

It provides a perturbative analysis of the Unruh effect under superluminal dispersion, revealing how the spectrum deviates from the standard Planckian form.

Findings

Superluminal dispersion induces corrections to the Unruh spectrum.

The corrections decrease as the threshold momentum $k_p$ increases.

The spectrum approaches the standard Planckian form for large $k_p$.

Abstract

In the context of quantum gravity phenomenology, we study the Unruh effect in the presence of superluminal dispersion relations. In particular, we estimate the response function and the probability rate for an accelerated detector coupled to a massless scalar field, whose dispersion relation becomes essentially quadratic beyond a threshold momentum $k_p$. By means of perturbative analysis, we show that superluminal dispersion induces a correction to the Planckian spectrum, which tends to vanish as $k_p$ increases.