[gus_massa]

It's difficult to know, but I'll copy one of my comments, with a few additions.

The problem is that (ignoring MA3) until the section "Predicting measurement results for the initial context" (inclusive) it is totally trivial if you have a background in Physics and Quantum Mechanics. It's not the usual model because it uses one (or two?) hidden variables, but it's easy to understand.

But the next section "Predicting measurement results for an arbitrary context" is totally unintelligible.

My guess is that the unintelligible part is hiding that when you measure a photon with a polarizer with an angle alpha, the other photon gets that information with an implicit faster than light communication. I have read it three times and I gave up.

To convince the scientific community it will be good to implement this model and post it in github or something.

* One function that create a pair of entangled photons X and Y.

* One function f that takes the photon X and the angle alpha and says if it passed the filter.

* One function g that takes the photon Y and the angle beta and says if it passed the other filter.

Bonus points if f and g are the same functions (or the only change is a pi/2).

No cheating, like using alpha in g, or assuming that alpha is 0.

Run a Montecarlo simulation and show that it gets the expected result. It's like 30 lines of Python or Fortran or whatever.

Transforming this to an analytical calculation is easy, but in an analytical calculations is easier to hide a change of variables and another trick that "transmit" alpha from one detector to the other.

[GistNoesis]

Would something like this do the trick : https://gist.github.com/unrealwill/2a48ea0926deac4011d268426...

(Straight implementation of Kupczynski Marian Closing the Door on Quantum Nonlocality https://philarchive.org/archive/KUPCTDv1 )

[gus_massa]

Exactly, something like that.

(Note for others: This is not an implementation of the OP method, it's another paper with a somewhat similar topic.)

It's an interesting model, but I don't like some details.

It generates a pair of (not entangled) photons with the same polarization (actually, +pi/2). Then it has two detectors.

In each detector the first secret parameter is equivalent to the usual calculation of the probability that a photon that has a polarization that is not aligned with the polarizer pass. If you can buy perfect/magical detectors that has the second secret parameter equal to zero, then this is just equivalent to the usual model with non entangled photons. And it should not break the Bell inequality.

The second secret parameter of each detector tries to model that the detectors sometimes miss a photon. I still don't like the model they are using, but it's not my specialty. Anyway, usually noise and fluky detectors make the result look more like classic results, so I expect that this second parameter makes the result not break the Bell inequality.

The problem is that it is possible to make very careful experiments that break the Bell inequality, so I don't understand what their model tries to show.

[GistNoesis]

Kupczynski is in the list of the reference pointed by OP method.

>The problem is that it is possible to make very careful experiments that break the Bell inequality, so I don't understand what their model tries to show.

Their plausible and local model aim to (and does!) reproduce the QM probabilities observed by experimenters (for all alpha and beta settings) and therefore does violate Bell inequality.

>It generates a pair of (not entangled) photons with the same polarization (actually, +pi/2)

The photon pair is entangled. The polarization is definite (and with a pi/2 offset between the pair) but unknown to the observer which is therefore measuring a distribution, that the key point. It's proposing an explanation of what entanglement is.

[gus_massa]

Looking more carefully at the paper you posted is that the filter is filtering too much.

If alpha=beta or alpha=beta+90°, then the number of coincidences is approximately 500,000 (of the 20,000,000 tries)

If alpha=beta+45°, then the number of coincidences is only 1,500. i.e. like 300 times smaller.

Such a difference is would be very easy to see experimentally, and it is not the case. The number of coincidences independent of the angle between the sensors (with some noise, as always).

This filter is picking only the photons that have an angle phi that is very close to (alpha+beta)/2 or (alpha+beta)/2+90°.

[GistNoesis]

This is a good point, but it's not as clear cut. The free parameter V helps trade-off this.

For example if you have V=9.0 for alpha=beta+90° you have nbselected = 5622861 and for alpha=beta+45° nbselected = 1527848 That's only 3.7 times smaller.

But the main point of the paper is to have a really simple model to highlight the pointlessness of Bell theorem rather than point to a specific mistakes by experimenters.

[gus_massa]

But if you use V=9.0, now the result of the simulation is not longer equal to the experimental result. For example with alpha=0, beta=90, V=9, if I run the simulation 10 times I get

  0.9536987797308330
  0.9540514229678816
  0.9534108516112525
  0.9540204547111079
  0.9535252821469831
  0.9538811736228740
  0.9541386030170054
  0.9534090666514868
  0.9538249532069655
  0.9535418321159825

That is pretty consistently like 0.045 less than the expected result that is 1.0.

(It is weird, but if alpha=0, and V=9, and you change beta, then the error is very close to (45-beta)/1000, where beta is in degrees. It's probably not exactly 1000, because using a number in degrees is weird, but it's similar.)

The problem is not to find an alternative algorithm that predicts one of the results, the problem is finding one that predicts correctly all the results.