Stability of Closed Time-Like Curves: Current Status?

[ksy]

I remember reading something, long ago, to the effect that any attempt at creating a CTC would be doomed by energy from vacuum fluctuations piling up through it and leading to explosive behavior (I think the idea originated in work done by Misner and Taub in 1969?).

Does anyone know what is the current status of this particular issue?

Thanks in advance!

 

[bcrowell]

A couple of sources of information:

http://en.wikipedia.org/wiki/Chronology_protection_conjecture

http://philsci-archive.pitt.edu/4240/

 

[tom.stoer]

As far as I remember the stability issue has been discussed for artificial situations like traversable wormholes. But there are cosmological solutions like the Gödel where these ideas do not apply. Now one could argue that we do not live in a Gödel universe, therefore we do no need to care about it; but I think that there is no known principle or mechanism ruling such a global solution containing CTCs.

 

[ksy]

Thanks a lot to both of you. So the problem would not arise for a solution like the one Ron Mallett's machine is based on?

 

[PAllen]

Thanks a lot to both of you. So the problem would not arise for a solution like the one Ron Mallett's machine is based on?

Any finite size version of Mallet's proposal that does not already contain a naked singularity is impossible without violating the weak energy condition. This means that some amount of exotic matter would be required, yet his machine provides no mechanism for its production (there is no known or even proposed method for producing anything except tiny amounts of matter/energy violating the weak energy condition). Basically, essentially all GR researches believe his proposal if formally refuted in peer reviewed papers he has never answered.