Keele Research Repository
Explore the Repository
Austin, J (2020) Do causality violations initiating a compactly generated Cauchy horizon require exotic matter? N/A. (Unpublished)
Causality violation.pdf - Draft Version
Download (92kB) | Preview
Abstract
This short paper summarises the proof that a causality violation formed from a bounded region requires matter that violates the null energy condition. Therefore the answer to the question in the title is yes. This is one of the results on which Stephen Hawking based his Chronology protection conjecture. It is conjectured that the required negative mass density fields cannot cover sufficiently large regions of space-time to make causality violations a reality. This lends support to the idea that the evolution of the universe is an entirely unitary process. This work is intended to be more accessible than Hawking’s original, which was cast in terms of the Newman-Penrose formalism.
Item Type: | Article |
---|---|
Additional Information: | Currently a working paper. Amendments may have been made from the point of deposit. |
Uncontrolled Keywords: | causality violation, energy condition, expansion, chronology protection |
Subjects: | Q Science > Q Science (General) Q Science > QA Mathematics Q Science > QC Physics |
Divisions: | Faculty of Natural Sciences > School of Computing and Mathematics |
Depositing User: | Symplectic |
Date Deposited: | 13 Aug 2020 10:57 |
Last Modified: | 23 Feb 2022 08:39 |
URI: | https://eprints.keele.ac.uk/id/eprint/8539 |