Quantum time machine

TL;DR

This paper proposes a modified version of Misner space that allows for a quantum-stable time machine by ensuring the regularity of the stress-energy tensor and circumventing Hawking's chronology protection, suggesting possible sub-microscopic time travel.

Contribution

It introduces a topological restriction leading to a modified Misner space where quantum effects stabilize a time machine, challenging the traditional chronology protection conjecture.

Findings

Stress-energy tensor is regular everywhere in the modified space

A quantum-stable, sub-microscopic time machine can be constructed

Hawking's chronology protection conjecture can be bypassed

Abstract

The continuation of Misner space into the Euclidean region is seen to imply the topological restriction that the period of the closed spatial direction becomes time-dependent. This restriction results in a modified Lorentzian Misner space in which the renormalized stress-energy tensor for quantized complex massless scalar fields becomes regular everywhere, even on the chronology horizon. A quantum-mechanically stable time machine with just the sub-microscopic size may then be constructed out of the modified Misner space, for which the semiclassical Hawking's chronology protection conjecture is no longer an obstruction.