No time machines in classical general relativity
Reads0
Chats0
TLDR
In this paper, it was shown that any extendible spacetime U has a maximal extension containing no closed causal curves outside the chronological past of U. The authors interpreted this fact as the impossibility of time machines.Abstract:
Irrespective of local conditions imposed on the metric, any extendible spacetime U has a maximal extension containing no closed causal curves outside the chronological past of U. We prove this fact and interpret it as impossibility (in classical general relativity) of the time machines, insofar as the latter are defined to be causality-violating regions created by human beings (as opposed to those appearing spontaneously).read more
Citations
More filters
BookDOI
The causal hierarchy of spacetimes
Ettore Minguzzi,Miguel Sánchez +1 more
TL;DR: In this article, the full causal ladder of spacetimes is constructed, and their updated main properties are developed, with emphasis in minimum hypotheses, and the implications of the recently solved "folk questions on smoothability", and alternative proposals (as recent isocausality), are also summarized.
Journal ArticleDOI
Lorentzian causality theory
TL;DR: In this paper, a review of Lorentzian causality theory is presented, paying particular attention to the optimality and generality of the presented results, including complete proofs of some foundational results that are otherwise difficult to find in the literature (e.g. equivalence of some Lorentziian length definitions, upper semi-continuity of the length functional, corner regularization, etc.).
Journal ArticleDOI
Do the Laws of Physics Forbid the Operation of Time Machines
TL;DR: The verdict on the question of whether it is possible to operate a time machine by manipulating matter and energy so as to manufacture closed timelike curves is that no result of sufficient generality to underwrite a confident “yes” has been proven.
Journal ArticleDOI
Static negative energies near a domain wall
Ken D. Olum,Noah Graham +1 more
TL;DR: In this paper, it was shown that a system of a domain wall coupled to a scalar field has static negative energy density at certain distances from the domain wall, which is a simple, explicit example of violation of the averaged weak energy condition and the quantum inequalities by interacting quantum fields.
Journal ArticleDOI
Chronological Spacetimes without Lightlike Lines are Stably Causal
TL;DR: In this paper, it was shown that spacetimes which are free from singularities admit a time function and hence admit a singularity, which is the worst possible violation of chronology.
References
More filters
Journal ArticleDOI
Wormholes, time machines, and the weak energy condition.
TL;DR: It is argued that, if the laws of physics permit an advanced civilization to create and maintain a wormhole in space for interstellar travel, then that wormhole can be converted into a time machine with which causality might be violatable.
Journal ArticleDOI
Chronology protection conjecture
TL;DR: In this paper, it has been suggested that an advanced civilization might have the technology to warp spacetime so that closed timelike curves would appear, allowing travel into the past.
Book
Techniques of Differential Topology in Relativity
TL;DR: In this article, the specialist in relativity theory with some global techniques for the treatment of space-times and will provide the pure mathematician with a way into the subject of general relativity.