Locality in correlated systems

[Dirkman]

It looks like so far Jay Yablon has reached the conclusion that bell is a self fullfilling tautology because one already excludes strong correlations from the definition of locality.

Which is funny cause I have seen a lot of talk on physicsforums about locality in QFT being based on the Cluster Decomposition Property which already excludes correlated systems.

[Joy Christian]

It looks like so far Jay Yablon has reached the conclusion that bell is a self fullfilling tautology because one already excludes strong correlations from the definition of locality.

Which is funny cause I have seen a lot of talk on physicsforums about locality in QFT being based on the Cluster Decomposition Property which already excludes correlated systems.

Locality in QFT concerns the standard signalling locality of special relativity, whereas locality in the context of Bell's theorem concerns no-signalling non-locality.

I am yet to be convinced by Jay's argument. He is constantly being misled by the Bell-believers at Retraction Watch, so it will take awhile to sort out all kinds of confusions over there. It would be fantastic of course if Jay's argument holds, but I very much doubt it. He has his work cut out to convince everyone, including me.

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[Dirkman]

It just seems to me that he reached the same conclusion that some have said before, including on this forum

"That is, by defining locality such that there can be NO STRONG CORRELATION between Alice’s settings and Bob’s measurements and vice versa, then your are DEFINING local theories to be impossible, because QM DOES CREATE STRONG CORRELATIONS!

Then, when you say that you have proved it is impossible for LRHV theories to describe strong QM correlations, you are saying that YOU HAVE PROVED YOUR DEFINITION, which is a self-fulfilling tautology! The failure of LRHV theories then BAKED INTO THE CAKE by supplementing the necessary and sufficient “25%-each pair by coin toss / no-communication between Alice and Bob / all terms with the same N” definition of locality, with an unnecessary and indeed tainted definition which says that Bob’s outcomes cannot correlate to Alice’s settings or vice versa. And this, we know is doomed from the start."

[Dirkman]

Quick layman question: Is your S3 theory related in any way to space-time symmetries ?

[Joy Christian]

Quick layman question: Is your S3 theory related in any way to space-time symmetries ?

Yes, S^3 is one of the well known solutions of Einstein's field equations of general relativity, which is our best theory of space-time.

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[minkwe]

Unfortunately, it appears to me that the thread at RW has become an infinite loop in which arguments are debunked and new participants (or puppets of old ones) show up repeating the same stale arguments over and over. Here is my latest and probably my last post there:

I would be surprised because if I took an Nx4 matrix with every cell filled by a +1 or a -1, which we agree cannot exceed the bound 2, and tried to turn it in to a matrix like one would see in an actual experiment, by randomly replacing one of the two Alice observations with an NA and one of the two Bob observations with an NA, then for a LARGE number of rows, the lhs calculation would have almost no chance of exceeding the bound 2 by a statistically significant amount. Try it in R. (The choice of where to put the NA’s must be random and independent of what the rows look like.)

That argument which was first proposed by Gill fails for several reasons:

1) The 4 Nx2 spreadsheets you generate in this way are not statistically independent, but the 4 Nx2 spreadsheets in experiments used to calculate ⟨A₁B₁⟩ + ⟨A₂B’₂⟩ + ⟨A’₃B₃⟩ – ⟨A’₄B’₄⟩ are independent.

2) Even if they were independent (which they aren’t cf (1)), it is not true that Local Realistic theories MUST produce an Nx4 spreadsheet of outcomes. The EPR elements of reality do not have to be the outcomes themselves. Just because the outcomes may not be simultaneously available does not mean the hidden elements of physical reality are not simultaneously present.

3) It is a fact that the outcomes in the EPRB experiment are not simultaneously available so a 4xN spreadsheet does not exist for that experiment, irrespective of the kind of theory you want to use to model it.

4) Even if a 4xN spreadsheet of outcomes existed (which it does not cf (3)), and even if the 4 disjoint Nx2 spreadsheets were independent (which they are not cf(1)), the cyclical recombination of rows in the paired Nx2 spreadsheets means that it is not always possible to faithfully sample the Nx4 spreadsheet using data from 4 separate disjoint Nx2 spreadsheets (see http://www.panix.com/~jays/vorob.pdf)

5) Anything you try in R will be one specific model (your imagination) of what a hidden variable theory is. Just because your imagined model does not exceed the bound says absolutely nothing about the possibility of any other model violating it. In other words, the probability of find a model which violates it may be 0.00001. So long as it is not 0, the argument fails. It does not help pro-Bell one iota to suggest that the probability of finding a model which exceeds 2 is low. You need to show that it is P=0.

6) See https://arxiv.org/pdf/0907.0767.pdf, https://arxiv.org/pdf/1108.3583.pdf, https://arxiv.org/pdf/1605.04887.pdf