Can we detect "Unruh radiation" in the high intensity lasers?

TL;DR

This paper reviews recent analysis on the possibility of detecting Unruh radiation in high-intensity laser experiments, focusing on thermalization processes and interference effects that may influence observability.

Contribution

It provides a detailed analysis of Unruh radiation detection prospects, especially considering thermalization in scalar QED and the associated relaxation time.

Findings

Thermalization time of an accelerated particle in scalar QED is derived.

Interference effects may cancel the expected Unruh radiation.

Detection of Unruh radiation remains challenging due to these effects.

Abstract

An accelerated particle sees the Minkowski vacuum as thermally excited, which is called the Unruh effect. Due to an interaction with the thermal bath, the particle moves stochastically like the Brownian motion in a heat bath. It has been discussed that the accelerated charged particle may emit extra radiation (the Unruh radiation) besides the Larmor radiation, and experiments are under planning to detect such radiation by using ultrahigh intensity lasers. There are, however, counterarguments that the radiation is canceled by an interference effect between the vacuum fluctuation and the radiation from the fluctuating motion. In this reports, we review our recent analysis on the issue of the Unruh radiation. In this report, we particularly consider the thermalization of an accelerated particle in the scalar QED, and derive the relaxation time of the thermalization.