Traversable acausal retrograde domains in spacetime
Abstract
In this paper we present geometry which has been designed to fit a layperson’s description of a ‘time machine’. It is a box which allows those within it to travel backwards and forwards through time and space, as interpreted by an external observer. Timelike observers travel within the interior of a ‘bubble’ of geometry which moves along a circular, acausal trajectory through spacetime. If certain timelike observers inside the bubble maintain a persistent acceleration, their worldlines will close.
Our analysis includes a description of the causal structure of our spacetime, as well as a discussion of its physicality. The inclusion of such a bubble in a spacetime will render the background spacetime non-orientable, generating additional consistency constraints for formulations of the initial value problem. The spacetime geometry is geodesically incomplete, contains naked singularities, and requires exotic matter.- Publication:
-
Classical and Quantum Gravity
- Pub Date:
- May 2017
- DOI:
- 10.1088/1361-6382/aa6549
- Bibcode:
- 2017CQGra..34i5006T