A Self-Consistent Vacuum for Misner Space and the Chronology Protection Conjecture

TL;DR

This paper constructs a self-consistent vacuum state in Misner space where the renormalized stress-energy tensor vanishes, indicating no inherent quantum instabilities or paradoxes for time travel, though individual travelers may still pose risks.

Contribution

It introduces an 'adapted' vacuum in Misner space with zero stress-energy tensor, addressing issues related to quantum effects and the chronology protection conjecture.

Findings

The adapted vacuum yields zero renormalized stress-energy tensor throughout Misner space.

A particle detector in this vacuum detects no particles, indicating a stable quantum state.

Misner space with this vacuum does not inherently prevent time travel.

Abstract

In this paper we find a self-consistent vacuum for Misner space. For this "adapted" Rindler vacuum the renormalized stress-energy tensor is zero throughout the Misner space. A point-like particle detector traveling on a timelike geodesic in a Misner space with this vacuum detects nothing. Misner space with this vacuum thus creates no problems for time travel in and of itself but a time traveler may pose a danger to himself and to the spacetime.