# Model used to refute Bell's theorem

• I
Summary:
The model used to refute Bell's theorem in a recent paper doesn't seem to be consistent with QM
I’m looking over a recent paper mentioned in another thread. It claims to refute Bell’s theorem. At first glance, the model presented in the paper doesn’t appear consistent with QM. Here’s a simple example.

Suppose we set both polarizers to the same angle ##\alpha = \pi /4##. In the model presented, A=1 (photon 1 passes its polarizer) when ##\lambda \leq \cos^2(\pi/4-\varphi_1)##, and B=1 when ##\lambda \leq \cos^2(\pi/4-\varphi_2)##. Using the initial condition ##\varphi_1=0,\varphi_2=\pi/2## as in the examples in the paper both inequalities reduce to ##\lambda \leq 0.5##. So the two photons yield the same result when measured about the same axis. As shown in the paper around Eqn 8, they also give the same result when measured about orthogonal axes.

So it seems this model is not consistent with QM (or I made an arithmetic error).

Doc Al, PeroK and Demystifier

Demystifier
Gold Member
The model used to refute Bell's theorem in a recent paper doesn't seem to be consistent with QM
I suspected that too, I'm glad that someone actually checked it.

Doc Al and PeroK
Summary:: The model used to refute Bell's theorem in a recent paper doesn't seem to be consistent with QM

I’m looking over a recent paper mentioned in another thread. It claims to refute Bell’s theorem. At first glance, the model presented in the paper doesn’t appear consistent with QM. Here’s a simple example.

Suppose we set both polarizers to the same angle ##\alpha = \pi /4##. In the model presented, A=1 (photon 1 passes its polarizer) when ##\lambda \leq \cos^2(\pi/4-\varphi_1)##, and B=1 when ##\lambda \leq \cos^2(\pi/4-\varphi_2)##. Using the initial condition ##\varphi_1=0,\varphi_2=\pi/2## as in the examples in the paper both inequalities reduce to ##\lambda \leq 0.5##. So the two photons yield the same result when measured about the same axis. As shown in the paper around Eqn 8, they also give the same result when measured about orthogonal axes.

So it seems this model is not consistent with QM (or I made an arithmetic error).
In the 2nd case you have delta <0. Equations (2) and (3) hold for 0<delta<pi/2.
What to do with other values of delta is described below eq. (3). For the case mentioned above it turns out that B=-1.

PeterDonis
Mentor
2020 Award
It claims to refute Bell’s theorem.
The original thread title did, but in the course of the thread the OP admitted that that claim is not correct. That's why the thread was closed.

This is not true. I did not admit the claim is not correct. The claim is still to refute Bell' theorem.
The reason is that Bell had claimed no local realistic model were possible at all without referring to his assumptions which don't cover thinkable contextual models. So the model presented in the paper which reproduces the QM correlations refutes Bell's theorem.
This was accepted by EPL (Europhysics Letters)

weirdoguy
PeterDonis
Mentor
2020 Award
This is not true.
Sorry, but this was discussed in the previous thread. That discussion is off topic in this thread. This thread is about whether the model presented in the paper is consistent with QM.

This was accepted by EPL (Europhysics Letters)
Acceptance of a paper by a journal is no guarantee that the paper is correct.

Acceptance of a paper by a journal is no guarantee that the paper is correct.
So far nobody has found a bug in my paper

weirdoguy
Demystifier
Gold Member
So far nobody has found a bug in my paper
You mean, nobody found a bug that you accepted to be a bug.

Dale and weirdoguy
If you say there was a bug, you should describe it precisely so that everyone can understand what you mean.

weirdoguy
Demystifier
Gold Member
If you say there was a bug, you should describe it precisely so that everyone can understand what you mean.
I did it in the closed thread. I've got many likes, so I think many (but not all) understood my points and agreed with me.

Demystifier
Gold Member
So far nobody has found a bug in my paper
Was your paper accepted in the first journal to which you submitted it? If not, would you dare to tell us in how many journals the paper was rejected? Would you share the referee reviews from those journals? Perhaps some of those spotted some bugs that you didn't accept as such.

In order to disprove the model of the paper one has to refer to it and prove a contradiction. Nobody has done it so far.

weirdoguy
Demystifier
Gold Member
In order to disprove the model of the paper one has to refer to it and prove a contradiction. Nobody has done it so far.
To prove that QM is compatible with locality, in principle you need to disprove all proofs of non-locality, it's not sufficient to disprove just one of the Bell's proofs. For instance, can you disprove the GHZ proof of nonlocality? That is, can you construct a local contextual model compatible with QM predictions for the GHZ state? For a simple presentation of the GHZ proof see my http://thphys.irb.hr/wiki/main/images/a/a1/QFound2.pdf pages 11-13.

To prove that QM is compatible with locality, in principle you need to disprove all proofs of non-locality, it's not sufficient to disprove just one of the Bell's proofs.
The opposite is the case as I wrote already in the closed tread:

Bell's theorem was refuted because he ignored contextual models in his reasoning. This also applies to any other theorem that claims that no local realistic model for quantum effects is possible, if they fail to rule out contextual models. These include, for example, the theorems of CHSH, GHZ and Hardy.

weirdoguy
Demystifier
Gold Member
Bell's theorem was refuted because he ignored contextual models in his reasoning.
But I explained you (in the closed thread) that he did not ignore contextual models in his reasoning.

Call it as you like it, he definitely ignored the kind of my model as this reproduces the QM correlations.

weirdoguy
Demystifier
Gold Member
I think your model is in fact nonlocal. This is seen in the paragraph around Eq. (9). In particular, before (9) you say that you use
$$\delta=\alpha + \pi/2 -\beta$$
It's not clear to me how exactly did you get this formula, but this formula is nonlocal. It is nonlocal because ##\alpha## is a property of one particle, while ##\beta## is a property of the other particle. Or if you still claim that this formula has a local origin, it would help if you could better explain how did you obtain this formula, because to me it's not clear from the paper.

Nullstein
Call it as you like it, he definitely ignored the kind of my model as this reproduces the QM correlations.
Bell's inequality holds for contextual models as well. If your model reproduces the QM predictions, then it must take one of the known outs, such as non-locality, superdeterminism or retrocausality. There are other models like this, so it would be nothing new or spectacular.

Demystifier
Gold Member
If your model reproduces the QM predictions, then it must take one of the known outs, such as non-locality, superdeterminism or retrocausality.
My post #17 indicates that his model is in fact non-local.

Nullstein
PeterDonis
Mentor
2020 Award
@emuc, repeated assertion is not argument. Nor is ignoring the actual statements made in the OP of this thread about the paper. Since you are either unable or unwilling to actually address what others are saying, this thread is closed. Further attempts on your part to make claims about your paper will receive a warning.