String theory and Bell's theorem, redux

1. Mar 8, 2008

Aeroflech

I asked this in sci.physics.strings and I haven't gotten an answer yet, so I hope you'll oblige me.

2. Mar 10, 2008

Demystifier

It is generally believed that string theory has nothing to say about quantum nonlocalities such as those related to the Bell theorem. For a different opinion see however
http://xxx.lanl.gov/abs/hep-th/0605250

3. Mar 11, 2008

Aeroflech

I think it is rather naive, and perhaps even disingenuous to call it non-locality when it disappears in certain interpretations. Also, http://physicsworld.com/cws/article/news/27640" [Broken] article raises the possibility that non-locality may not even be enough. (Though I don't think that this would affect the Bohmian interpretation. Also, I'm don't know how well verified those results are.)

Last edited by a moderator: May 3, 2017
4. Mar 12, 2008

Demystifier

OK, let me explain what the Bell theorem says:
It says that reality either
a) does not exist
or
b) is nonlocal and contextual
The paper that you mention, indeed, also shows that nonlocality is not enough, but that contextuality is also needed in order to have reality. (BTW, Bohmian mechanics is both nonlocal and contextual, so you are right that it is not excluded by results of the the paper that you mention.)
Nevertheless, contextuality is usually not considered to be an unacceptable property. What is considered unacceptable is nonlocality. That is why non-real interpretations of quantum mechanics are widely accepted.

And now comes string theory. Various results in string theory (that have no analog in particle physics or field theory) show that a certain form of nonlocality cannot be avoided. As it cannot be avoided, now nonlocality becomes acceptable. With nonlocality being acceptable, the main argument against reality cannot longer be applied. In that sense, with string theory reality becomes more acceptable.

Even with accepting reality, there is still many possibilities. Nevertheless, an independent argument
http://xxx.lanl.gov/abs/hep-th/0512186
shows that the Bohmian interpretation is quite natural within string theory. (This argument that does not have an analog in particle physics.)

In addition, string theory solves some intrinsic problems of Bohmian mechanics that cannot be solved so elegantly within particle or field physics:
http://xxx.lanl.gov/abs/hep-th/0702060
http://xxx.lanl.gov/abs/0705.3542

Thus, although the things are not yet settled, some results do point in the direction that string theory and Bohmian mechanics are naturally related.

Last edited: Mar 12, 2008
5. Mar 12, 2008

Demystifier

See also the argument that, in a certain sense, quantum mechanics is nonlocal in ANY interpretation:
http://xxx.lanl.gov/abs/quant-ph/0703071