Relativistic Quantum Measurements, Unruh effect and Black Holes

TL;DR

This paper applies restricted path integrals to analyze relativistic quantum measurements, clarifying the physical nature of thermal effects like the Unruh and Hawking effects, and distinguishing real from virtual particles in different black hole scenarios.

Contribution

It introduces the use of restricted path integrals for analyzing relativistic measurements and clarifies the physical reality of thermal particles in black hole and acceleration contexts.

Findings

Thermal particles are real only in black hole formation scenarios.

In eternal black holes, thermal particles are indistinguishable from real particles but do not affect black hole mass.

In the Unruh effect, thermal particles are virtual and not physically real.

Abstract

It is shown how the technique of restricted path integrals (RPI) or quantum corridors (QC) may be applied for the analysis of relativistic measurements. Then this technique is used to clarify the physical nature of thermal effects as seen by an accelerated observer in Minkowski space-time (Unruh effect) and by a far observer in the field of a black hole (Hawking effect). The physical nature of the "thermal atmosphere" around the observer is analysed in three cases: a) the Unruh effect, b) an eternal (Kruskal) black hole and c) a black hole forming in the process of collapse. It is shown that thermal particles are real only in the case (c). In the case (b) they cannot be distinguished from real particles but they do not carry away mass of the black hole until some of these particles are absorbed by the far observer. In the case (a) thermal particles are virtual.