A new realistic stochastic interpretation of Quantum Mechanics

[DrChinese]

1. The point is that it seems to be the case that if you take all of the possible data from 2 & 3, there is always ways of sorting the data where you have Bell state correlations, separable correlations and no correlations whatsoever. The fact that you can mix the Bell state data and make the correlations in other bases disappear is indicative of this because even though those correlations have disappeared, its just the same data mixed up. The new mixed up data is then statistically the same as the separable measurements data (even though it is made up of swap data).

And this is also pretty clearly the case in the part where they unambiguously describe mixing Bell states and report the statistical correlations they do and do not find. The mixing I am referring to is very unambiguously decribed in the paper you linked. I think you need to re-read that part of the paper.


2. They are in precisely the sense I mean - in the sense that the particles possess correlations and if you should chose to make measurements you would find those correlations. The fact that you happen to choose to measure some bases or not is immaterial, just like the fact that the entangled photons will have correlations in all bases but you clearly cannot ever simultaneously measure them at the same time.

Again, just trying to present the actual facts.

1. There is no "mixing" in this paper, or any others I cite. Respected scientists do not "mix" statistics to deceive readers. They present a real effect that has been replicated in various manners in other experiments. I might have hoped that it would not be necessary to say that, since one of the authors shared a Nobel for this and other ground-breaking work. But perhaps some quotes from the paper itself will be convincing:

"Since Peres' proposal [circa 1999], there have been pioneering delayed entanglement swapping experiments. However, none of these demonstrations implemented an active, random and delayed choice, which is required to guarantee that the photons cannot know in advance the setting of the future measurement. Thus, these experiments in principle allowed for a spatiotemporal description in which the past choice event influences later measurement events. Our experiment demonstrates entanglement-separability duality in a delayed-choice configuration via entanglement swapping for the first time. This means that it is possible to freely and a posteriori decide which type of mutually exclusive correlations two already earlier measured particles have. They can either show quantum correlations (due to entanglement) or purely classical correlations (stemming from a separable state).

"For each successful run (a 4-fold coincidence count), not only Victor’s measurement event happens 485 ns later than Alice and Bob’s measurement events, but Victor’s choice happens in an interval of 14 ns to 313 ns later than Alice and Bob’s measurement events. Therefore, independent of the reference frame, Victor’s choice and measurement are in the future light cones of Alice and Bob’s measurements. Given the causal structure of special relativity, i.e. that past events can influence (time-like) future events but not vice versa, we explicitly implemented the delayed-choice scenario as described by Peres.

"Fig. 3A shows that when Victor performs the Bell-state measurement and projects photons 2 and 3 onto
|Φ−〉23, this swaps the entanglement, which is confirmed by significant correlations of photons 1 and 4 in all
three bases. ... On the other hand, when Victor performs the separable-state measurement on photons 2 and 3 and does not swap entanglement, the correlation only exists in the |𝐻〉/|𝑉〉 basis and vanishes in the |+〉/|−〉 and|𝑅〉/|𝐿〉 bases, as shown in Fig. 3B. This is a signature that photons 1 and 4 are not entangled but in a separable state. ... For each pair of photons 1&4, we record the chosen measurement configurations and the 4-foldcoincidence detection events. All raw data are sorted into four subensembles in real time according to Victor’s choice and measurement results. After all the data had been taken, we calculated the polarization correlation function of photons 1 and 4. It is derived from their coincidence counts of photons 1 and 4 conditional on projecting photons 2 and 3 to |Φ−〉23 = (|𝐻𝐻〉23 − |𝑉𝑉〉23)/√2 when the Bell-state measurement was performed, and to |𝐻𝐻〉23 or |𝑉𝑉〉23 when the separable state measurement [SSM] was performed."

Note that the only Bell state statistics that are being presented are for the |Φ−〉 case, and the |Φ+〉 case is not considered for technical reasons. For the Separable state stats, the comparable stats to the |Φ−〉 case are presented. The results are "apples to apples". It is a simple matter to see the critical difference between the 3a graph (Victor executes a swap) and the 3b graph. This difference is simply a result of Victor's decision (actually a random choice) to swap or not.

So no matter what you seem to think, there is a demonstrable effect that is strictly dependent on interfering overlap in the beamsplitter: "The Bell-state measurement (BSM) corresponds to turning on the switchable quarter-wave plates..." while the SSM (separable) corresponds to leaving them off. Note that other cited implementations of switching between the BSM vs. SSM (i.e. swap or not) use delay to create distinguishable photons.


2. There is no such thing as "transitive" statistical relationships between independently created entangled pair streams such as 1&2 and 3&4 (that would also yield a underlying relationship between 1&4). I don't know where you got this idea from, but you won't find any support for what you say in the literature. Although if I'm wrong, you can always correct me with a suitable citation.

A broken clock is right twice a day - and it is equally true that there is a basis (H/V specifically, as shown in Figure 3) which do correlate. But that correlation is quite limited, and can easily be seen for what it is. Look at the other bases such as +/- or L/R and you can see the unambiguous results.

 

[PeterDonis]

it seems to be the case that if you take all of the possible data from 2 & 3, there is always ways of sorting the data where you have Bell state correlations, separable correlations and no correlations whatsoever.

That's not how statistics is done on experiments. You don't look at all the possible ways of sorting data, because the vast majority of them are irrelevant. You look at the ways of sorting data that match up with the actual, physical things that were done in the experiment. In these experiments, an actual, physical thing was done at the BSM where photons 2 & 3 either do or do not interact, based on a choice made by the experimenter. So the sorting of the data that is relevant is the one that matches up with the choice that was made at the BSM, and the resulting measurements on photons 2 & 3. Any other sorting has no basis in scientific experimental practice.

 

[lightarrow]

TL;DR Summary: I attended a lecture that discussed the approach in the 3 papers listed below. It seems to be a genuinely new interpretation with some interesting features and claims.

These papers claim to present a realistic stochastic interpretation of quantum mechanics that obeys a stochastic form of local causality. (A lecture I recently attended mentioned these papers). It also claims the Born rule as a natural consequence rather than an assumption. This appears to me to be a genuinely new interpretation. I have not delved into the papers in detail, but figured some people here may be interested.

https://arxiv.org/abs/2302.10778
https://arxiv.org/abs/2309.03085
https://arxiv.org/abs/2402.16935

Barandes call it "Formulation" of QM, not "interpretation".

--
lightarrow

 

[iste]

There is no "mixing" in this paper,

I have given you the quote twice. You need to comment on the quote. It os unambiguous what is being said. I don't know why you seem to be in denial about this.

"Since Peres' ... was performed."

See the paper I link in post #396 for an alternative perspective. It ironically also seems pretty clear that the authors of the Ma paper endorse a similar kind of view.

It is a simple matter to see the critical difference between the 3a graph (Victor executes a swap) and the 3b graph. This difference is simply a result of Victor's decision (actually a random choice) to swap or not.

And it is also easily seen in thr paper that 3b can be recreated by simply mixing up the Bell state data. Yes, Victor decides to make a swap but you can make a decision to physically interact with a system which leads the data to be sorted in different ways. For instance, this is what the beam splitter is doing in the paper in post #396; it is just affecting where the photons end up on the idler screens which leads to the consequence that if you just add the interference patterns on the idler screens together, they just reproduce the two clumps of the other which-way screens and signal screens. This seems strongly analogous to how the coherence conditions' data in the entanglement swapping experiment just sum up to produce the statistics of the other separable data. You have a physical event here which just affects the how data is sorted from other events that we already knew were going to happen. On the eraser experiment, we already knew the photons were going to go through one slit or the other; in the swapping experiment, we already knew what kinds of results that two different entanglement experiments were going to have.

So no matter what you seem to think, there is a demonstrable effect that is strictly dependent on interfering overlap in the beamsplitter: "The Bell-state measurement (BSM) corresponds to turning on the switchable quarter-wave plates..." while the SSM (separable) corresponds to leaving them off. Note that other cited implementations of switching between the BSM vs. SSM (i.e. swap or not) use delay to create distinguishable photons.

Again, I have already agreed with this several times already and mentioned how Barandes' formulation plausibly includes this phenomena and how it may relate to the swap.

There is no such thing as "transitive" statistical relationships between independently created entangled pair streams such as 1&2 and 3&4 (that would also yield a underlying relationship between 1&4).

Its a generic property any correlations can have aslong as you can establish correlations between 2&3, for instance using a bell-state or separable-state measurement. Because these measurements pick out different correlations, the correlations you can expect to find in 1&4 will be different. The only thing you need is the assumption that 1&2 are correlated, the assumption that 3&4 are correlated, and something that allows you to establish a correlation between 2&3, for instance by measurement of coincidences or states which possess certain coincidences.

Look at the other bases such as +/- or L/R and you can see the unambiguous results.

Why do you think that the Barandes view or the conditioning view cannot account for them? It makes complete sense as long as you do the Bell state measurement which effectively can pick out those correlations which are then inherited by 1&4 in virtue of the transitivity that now connects 1, 2, 3 and 4.

 

[Lord Jestocost]

TL;DR Summary: I attended a lecture that discussed the approach in the 3 papers listed below. It seems to be a genuinely new interpretation with some interesting features and claims.

These papers claim to present a realistic stochastic interpretation of quantum mechanics that obeys a stochastic form of local causality. (A lecture I recently attended mentioned these papers). It also claims the Born rule as a natural consequence rather than an assumption. This appears to me to be a genuinely new interpretation. I have not delved into the papers in detail, but figured some people here may be interested.

https://arxiv.org/abs/2302.10778
https://arxiv.org/abs/2309.03085
https://arxiv.org/abs/2402.16935

Barandes call it "Formulation" of QM, not "interpretation".

--
lightarrow

This might explain why Barandes has to use "peculiar" formulations such as "More precisely, interference is nothing more than a generic discrepancy between actual indivisible stochastic dynamics and hypothetically divisible stochastic dynamics."(in https://arxiv.org/abs/2302.10778).

Would this “generic discrepancy” - and how in a physical model - elucidate, for example, the experiments on the double-slit diffraction of neutrons?

 

[lightarrow]

This might explain why Barandes has to use "peculiar" formulations such as "More precisely, interference is nothing more than a generic discrepancy between actual indivisible stochastic dynamics and hypothetically divisible stochastic dynamics."(in https://arxiv.org/abs/2302.10778).

Would this “generic discrepancy” - and how in a physical model - elucidate, for example, the experiments on the double-slit diffraction of neutrons?

Why this peculiar case shoud be different from the general one he addresses?

--
lightarrow

 

[DrChinese]

1. I have given you the quote twice. You need to comment on the quote. It os unambiguous what is being said. I don't know why you seem to be in denial about this.

2. See the paper I link in post #396 for an alternative perspective.

3. And it is also easily seen in the paper that 3b can be recreated by simply mixing up the Bell state data. Yes, Victor decides to make a swap but you can make a decision to physically interact with a system which leads the data to be sorted in different ways.

4. Why do you think that the Barandes view or the conditioning view cannot account for them? It makes complete sense as long as you do the Bell state measurement which effectively can pick out those correlations which are then inherited by 1&4 in virtue of the transitivity that now connects 1, 2, 3 and 4. ... There is always transitivity. A is only ever correlated with D because A is correlated with B is correlated with C is correlated with D, entanglement or separable.

1. You quoted the paper, yes:

"When Victor performs a BSM, photons 1 and 4 are only entangled if there exists the information necessary for Victor to specify into which subensembles the data are to be sorted. In our case the subensembles correspond to |Φ−〉23 or |Φ+〉23. Without the ability for this specification, he would have to assign a mixture of these two Bell states to his output state which is separable, and thus he could not correctly sort Alice's and Bob's data into subensembles. This is confirmed by evaluating the experimental data obtained in a BSM but without discriminating between |Φ−〉23 and |Φ+〉23. Then there exists a correlation only in the |𝐻〉/|𝑉〉 basis (0.55 ± 0.06) and no correlations in the |+〉/|−〉 (0.02 ± 0.05) and |𝑅〉/|𝐿〉 (0.01 ± 0.05) bases, similar to the situation when Victor performs a separable-state measurement."

But you completely missed what is being pointed out by the quote, and it in no way matches your ideas. They simply point out that if you don't discriminate between the 2 Bell states |Φ−〉23 and |Φ+〉23, there is no underlying Entangled state statistics. No surprise there, as they yield precisely opposite predictions - and you would expect correlations to cancel each other closely. And they do, just as they report... which is simply for completeness, to show that there were no entangled correlations to begin with.

2. It's a shame that the Nobel committee overlooked this [/sarcasm]brilliant and well-accepted[/end sarcasm] work by Fankhauser when vetting Zeilinger for the Physics Nobel. If they had read it, they certainly would have crossed off Zeilinger's name for the prize.

3. There is no mixing of data!

The graphs of 3a and 3b only include the same signatures for the 2 & 3 photons. That is the signature for the Entangled |Φ−〉23 Bell state for 3a, and the signature for the same state but Separable version (not entangled) in 3b. The signature in either case is exactly the same: 2&3 are marked as HH or VV. These cases are combined, although it wouldn't matter if they were or not. But there is NO MIXING of the |Φ−〉23 and |Φ+〉23 subensembles as you state/imply. The |Φ+〉23 subensemble is not reported on in Figure 3, that is the subensemble where the 2&3 photons are marked as HV or VH. From the paper:

"Then the same coincidence counts (HH and VV combinations of Victor’s detectors) are taken for the computation of the correlation function of photons 1 and 4. These counts can belong to Victor obtaining the entangled state |Φ−〉23 in a BSM or the states |𝐻𝐻〉23 and |𝑉𝑉〉23 in an SSM. For the details, see Supplementary information."

3a: |Φ+〉23 means HH or VV. The 3 mutually unbiased bases are H/V, +/-, L/R, all of which show strong correlation.

3b: |Φ+〉23 means HH or VV (same signature, but Separable rather than Entangled). The 3 mutually unbiased bases are H/V, +/-, L/R, only the first of which shows correlation.

(The 3 bases are selected by Alice and Bob, which occurs prior to Victor's measurement. )

As you say, "a decision to physically interact" does in fact change which bucket the data point is added to. 3a is the bucket ONLY for physical interactions, 3b is the bucket for NO physical interaction. You can't change buckets once they are defined this way, at least not in a science experiment.

4. There is no such thing as "transitivity" of entanglement, and I requested a suitable reference on this completely wrong idea.

When the 2 and 3 photons are correlated (both H or both V), this does not lead to any seemingly entangled correlation whatsoever between photons 1 and 4 EXCEPT when Alice and Bob measure them on the H/V basis. Either 1 and 4 become entangled due to the swap, or they don't. When they are entangled, the 1 & 4 photons will be strongly correlated on ALL bases. If they are separable, that doesn't happen. The statistics, as shown in Fig 3, are completely different. If you were correct, those graphs would look alike. Again, this should be obvious - it's the main result of the paper! I know you can't think they are committing scientific fraud...

 

[iste]

But you completely missed what is being pointed out by the quote, and it in no way matches your ideas. They simply point out that if you don't discriminate between the 2 Bell states |Φ−〉23 and |Φ+〉23, there is no underlying Entangled state statistics

Yes, the fact that not discriminating Bell states removes the correlations is precisely my point. You can clearly have separable measurements of HHVV which have Bell statistics embedded in them that are not distinguished by those measurements. Cleaarly there is something lost in translation here because to me this paragraph looks like it is repeating what I said.

2. It's a shame that the Nobel committee overlooked this [/sarcasm]brilliant and well-accepted[/end sarcasm] work by Fankhauser when vetting Zeilinger for the Physics Nobel. If they had read it, they certainly would have crossed off Zeilinger's name for the prize.

I don't see any argument here and the paper clearly is not refuting anything about non-locality.

But there is NO MIXING of the |Φ−〉23 and |Φ+〉23 subensembles as you state/imply

Yes, there is no mixing of the separable and non-separable measurements. Just like in the delayed eraser experiment there are clearly different screens where the interference photons and which-way photons go. But if you mix the interference photo data it just adds together into the which-way data. Similarly here, the authors explicitly mixed the non-separable data and produced what is statistically indistinguishable from the separable data. The point is that the fact that there are some measurements with correlations in other bases and some measurements with correlations in only one base is not a miraculous point. Because the experiment clearly shows that you can go from one to the other by mixing the data, or using measurements that fail to make discriminations that a Bell state measurement would. We have two entangled systems which in virtue of their entanglement are always going to produce a predictable set of results if you measure them a bunch. Even if you measure an entangled system on different bases, you know what measurements you would have got had you measured them on the same basis. The Bell state and separable measurements are two ways in which we can establish coincidences between the two different entangled systems but one enables a different kind of coupling due to the coherence and phase that is not accessible in the separable case.
.

4. There is no such thing as "transitivity" of entanglement, and I requested a suitable reference on this completely wrong idea.

When the 2 and 3 photons are correlated (both H or both V), this does not lead to any seemingly entangled correlation whatsoever between photons 1 and 4 EXCEPT when Alice and Bob measure them on the H/V basis. Either 1 and 4 become entangled due to the swap, or they don't. When they are entangled, the 1 & 4 photons will be strongly correlated on ALL bases. If they are separable, that doesn't happen. The statistics, as shown in Fig 3, are completely different. If you were correct, those graphs would look alike. Again, this should be obvious - it's the main result of the paper! I know you can't think they are committing scientific fraud

The answer to this is that in the two parts of figure 3 we have two examples of transitivity: transitivity of separable correlations and the transitivity of entanglement correlations. If you have correlations for one basis for 2 and 3, then transitivity means only allowing correlations between 1 and 4 in one basis. If you have correlations for more than one basis for 2 and 3, then transitivity means you will have correlations between 1 and 4 in more than one basis.

I'm pretty sure this paper here evokes the same kind of idea of transitivity:

https://scholar.google.co.uk/scholar?cluster=10636160464314492908&hl=en&as_sdt=0,5&as_vis=1

e.g.

"Alice’s measurement ‘‘steers’’ the state of particle 2, which is sent to Vicky, in turn influencing the state of particle 3 (and hence also particle 4) through Vicky’s Bell-state measurement. This does involve spatial nonlocality (which was not at issue), but no temporal nonlocality. Finally, Bob performs a measurement on particle 4. Like was the case for the Ma et al.-experiment, the outcomes of the first and final measurement will in general not display Bell correlations. [But] If we post-select the subsample where the outcome of Vicky’s Bell-state measurement was ‘‘Bellstate
+’’, however, we do observe Bell correlations:"

"It is important to note that, similarly to the non-delayed case, the
correlations observed in the Ma et al. and Megidish et al. experiments only obtain if we sort the outcomes obtained by Alice and Bob in different subsamples corresponding to the possible outcomes of Vicky’s measurement, and consider the outcomes within each subsample. If we ignore the outcomes of Vicky’s measurement and consider all the outcomes obtained by Alice and Bob together, we will find no correlation. This suggests a different possible explanation of the Bell-type correlations; namely that they are a statistical artefact arising due to this post-selection, rather than any mark of genuine entanglement between particle 1 and particle 4."

As you say, "a decision to physically interact" does in fact change which bucket the data point is added to

And this distinction between separability and non-separability exists in the Barandes formulation.

I think something like the following is probably what would happen in the Barandes formulation. But before starting it has to be noted that what Barandes has done so far does not have the different bases or precisely modeled spin so this is a story of how the kinds of elements present in the Barandes theory would deal with entanglement swapping. But at the same time, the central idea of Barandes' theory is that any quantum system can be translated into an indivisible stochastic one so if he has not made an error, the indivisible stochastic model of entanglement swapping should be possible just in virtue of the fact we are talking about quantum systems.

Right, so you have two indivisible stochastic systems 1 & 2 and you let them locally interact, causing a correlation that leads to a non-separable composite system. The two parts of the composite system travel far apart but the correlation is maintained due to the memory of the composite indivisible transition matrix. We can say the same for indivisible stochastic systems 3 & 4.

We do a separable measurement which establishes a one-to-one correspondence for results of 2 & 3 in one basis effectively by picking out pairs of results. No coincidences in other bases are found for 2 & 3 because this requires a non-separable relationship between 2 & 3 which we do not have due to it being a separable measurement. The coincidences in 2 & 3 mean we can follow the following logic: result in 1 implied a result in 2. Result in 2 implies a result in 3, result in 3 implies result in 4. Because 2 & 3 would never show coincidences in other bases, this chain would be broken if we tried to follow it in the other basis.

Or we could do a non-separable measurement on 2 & 3 which not only establishes a one-to-one correspondence in one basis but implies this would be the case in all bases because it picks out a correlation or would-be-coincidences in all bases, the same kind of correlation that was implied by the local interactions that produce entanglement for 1 & 2 or 3 & 4 in the beginning. We can then follow the chain of reasoning suggested before but in all bases. Even if we measure 1(4) and 2(3) in different bases, the correlation between 1 & 4 is implied by the fact that if we had measured 2 in the same basis, we know what the answer would have been. We then know what the answer would have been in 3 which implies the result in 4 if you measure it in the relevant basis. We can then additionally look at the swap in the sense that a non-separable state has been created for 2 & 3. The Bell state measurement also then acts as a division event for systems 1 & 2 and 3 & 4, breaking their respective entanglements. However, we can still note the non-separable correlation present in 1 & 4 (due to the chain of reasoning before) which is just identical to an entanglement. Non-separable systems (entanglements) have been swapped between the 4 particles.

If we do not perform the measurements, no correlations between 1 & 4 occur because there is no one-to-one correspondence. 1 & 4 go through all their possible outcomes they were going to go through as an independent entangled system, 3 & 4 go through all their possible outcomes they were going to go through as an independent entangled system. No one-to-one correspondences of results have been established between 2 & 3 so if you examine all the possible outcomes of 2 and all the possible outcomes of 3 side-by-side, it just looks random because you are not isolating any specific sets of one-to-one correspondences.

Ofcourse, there is no physical collapse in Barandes' system. When the experimenter couples his measurement device to a system in general he cannot choose the measurements he finds. To isolate the individual outcomes of measurements in this formulation as you would need to for a Bell state (or separable) measurement, the only thing you can do is statistical conditioning (which is what Barandes identifies as the formal source of collapse). And when you condition on results of 2 & 3, only then can you follow the chains of correlations or coincidences above allowed respectively by non-separable and separable measurements.

In addition because there is no physical collapse and only statistical conditioning, delays do not matter. The correlations are established at source and just remembered until measurement as systems 1 & 2 or 3 & 4 evolves. It doesn't matter who measured what first because the remembered correlation dictates what is going to happen at measurement. The separable and non-separable measurements then just pick out one-to-one correspondences between 2 & 3.

 

[iste]

Would this “generic discrepancy” - and how in a physical model - elucidate, for example, the experiments on the double-slit diffraction of neutrons?

Its the same as the regular interference in quantum mechanics.

 

[pines-demon]

This might explain why Barandes has to use "peculiar" formulations such as "More precisely, interference is nothing more than a generic discrepancy between actual indivisible stochastic dynamics and hypothetically divisible stochastic dynamics."(in https://arxiv.org/abs/2302.10778).

Would this “generic discrepancy” - and how in a physical model - elucidate, for example, the experiments on the double-slit diffraction of neutrons?

Why neutrons specifically? It could help elucidate something if Barandes gave an interpretation to his indivisibility feature.

 

[Lord Jestocost]

Of course, you can do a double slit experiment with single electrons, too.

When someone is convinced “that physical models based on classical kinematics combined with stochastic dynamics can replicate all the empirical predictions of textbook quantum theory”, he should show that at least by means of simple examples.

 

[jbergman]

Of course, you can do a double slit experiment with single electrons, too.

When someone is convinced “that physical models based on classical kinematics combined with stochastic dynamics can replicate all the empirical predictions of textbook quantum theory”, he should show that at least by means of simple examples.

This part isn't surprising to me, that he can replicate predictions of textbook quantum theory.

What's more dubious for me are the claims by @iste in this thread that this how somehow implies particles have definite positions and locality under this interpretation.

If you take the definite positions statement as true then indivisibility implies non-locality, because locality would imply the ability to condition on the particles position at a nearby time.