I A new realistic stochastic interpretation of Quantum Mechanics

[Fra]

Bell's theorem works for as many hidden variables as you want, having a single one, two or more, as long as the variables are local, it does not allow to avoid the theorem.

Lets not forget the realism assumption, this is IMO the questionable one to me without going into details again, as i have seen this difficult-to-discuss topic without fleshing out a real toy model.

So the view I have from all this, is not a "realist stochastic HV model", but and interaction of multiple stochastic HV model, where the HV does not qualify as "real" as per Bells notion. And in a way each subsystem has its own "model" of reality. Such a picture would as a correpondence mate well with Baranders correspondnece in some limit. But such full models has not been show to be ruled out by bells ansatz.

So I supposed that what I envision would by most people be consider a very non-realist view, but while I personally see it as real, its just that I think that reality itself is subjective and emergent. This is very FAR from the "realism" as in "reveal pre-existing states" that bell entertains with his lambda.

Edit: I found another way of explaining my stance. Perhaps I could also say that the picture i try to paint is not really a hidden variable theory at all! I guess my point is that the word "hidden variable" has become claimed to mean something specific, but for me it more is a good way to label "emergent reality", which is hidden from other subsystems. But lets suppose reality is emergent in some way, and where this emergence happens in parallell in subsystems, then the "local reality" wouldnt be less real. And the connection to Barandes view is that someone I think that the transition matrices must somehow be emergent but this neither Barandes nor QM nor QFT explains. And here one also associates to what if this emergence can be built from self-organised scramblers? Ie. just like the only LAW the requires not further "explanation" is stochastics; the only form of "computation" that might not required any furher "explanation" seems to be scrambling, or random permutations. All these things... I find MUCH easier to thinkg about, in Barandes picture, than in hilbert picture for example. At least for me, it mates better with my intuition and agent based models.

/Fredrik

 

[Sambuco]

If the system remained non-factorizable then the measurement would directly affect the other system. The change to factorization is a requirement to stop the systems communicating like that, its not a sign of communication.

I agree with you that a measurement on one of the entangled particles constitutes a division event that restores factorization in the system, i.e. $\Gamma_{A,B}(t) = \Gamma_{A}(t) \otimes \Gamma_B(t)$ for $t > t_1$, where $t_1$ is the time at which Alice measures particle A, so as you said, this measurement stop any causal influence between A and B for $t > t_1$. However, what I want to enfatize is that what you called "change to factorization" is a nonlocal phenomenon. In other words, the question is whether the transition matrix $\Gamma_B(t)$ inmediately after the remote measurement on A performed by Alice, depends on the measurement outcome obtained by Alice. As the stochastic-quantum correspondence directly translates the wavefunction $\Psi_B(t)$ into $\Gamma_B(t)$, and we know from the math of QM that $\Psi_B(t)$ inmediately after Alice's measurement depends on the measurement outcome obtained by her, then, the transition matrix for particle B in Barandes' formulation also depends on the result of a remote measurement performed on the other particle.

But Barandes' seems to show in his locality paper that the measurement doesn't affect the transition probabilities for the spatially distant system.

That's not true. What Barandes proved is that QM formulated as a unistochastic process satisfies his new principle of "causal locality" which states that, if two localized systems remain spacelike separated during the time of a given physical process, they do not causally affect each other, in the sense that the conditional probabilities of one particle do not depend on what happens to the other.

There's no evidence for what you're saying in these papers.

I think it is quite the opposite. In the case of entanglement, Barandes says:

"The breakdown (60) in tensor-factorization for t ≥ t′ is precisely entanglement, as manifested at the level of
the underlying indivisible stochastic process. The factorization (58) therefore also breaks down, and so one can conclude that the two subsystems Q and R exert causal influences on each other, stemming from their local interaction at the time t′."

Lucas.

 

[iste]

However, what I want to enfatize is that what you called "change to factorization" is a nonlocal phenomenon.

Why? If I synchronize two clocks so they are in time and corrrlated ans then bring them far apart ans then mess with one of them so they are no longer synchronized, is that a non-local phenomenon? No. Nothing suggests the loss of (Edit)Non-factorization needs to involve some kind of non-local communication

In other words, the question is whether the transition matrix ΓB(t) inmediately after the remote measurement on A performed by Alice, depends on the measurement outcome obtained by Alice.

They don't.

What Barandes proved is that QM formulated as a unistochastic process satisfies his new principle of "causal locality" which states that, if two localized systems remain spacelike separated during the time of a given physical process, they do not causally affect each other, in the sense that the conditional probabilities of one particle do not depend on what happens to the other.

That's what I said!

As the stochastic-quantum correspondence directly translates the wavefunction ΨB(t) into ΓB(t), and we know from the math of QM that ΨB(t) inmediately after Alice's measurement depends on the measurement outcome obtained by her, then, the transition matrix for particle B in Barandes' formulation also depends on the result of a remote measurement performed on the other particle.

Yes but there is no explicit non-locality that cauases instantaneous changes either in quantum mechanics or Barandes' formulation. You don't need collapse to do quantum mechanics as Many World proponents will vehemently tell you. Beyond these facts then its just talking about a deeper underlying interpretation which is not inherent to Barandes' formulation.

The breakdown (60) in tensor-factorization for t ≥ t′ is precisely entanglement, as manifested at the level of
the underlying indivisible stochastic process. The factorization (58) therefore also breaks down, and so one can conclude that the two subsystems Q and R exert causal influences on each other, stemming from their local interaction at the time t

But those arent the measurement devices. The measurement devices dont affect the spatially distant system's probabilities. Q and R are correlated because their composite transition matrix remembers the initial locally induced correlation.

 

[iste]

Barandes in one of his papers says(https://arxiv.org/abs/2402.16935)

"plausibly resolves the measurement problem, and deflates various exotic claims about superposition, interference, and entanglement"

My question is, he talked about these subjects but did not elaborate on superposition. So How does superposition looked upon in his theory. For instance does a particle has a specific spin, or is it flip flopping up and down.

There is no metaphysical superposition. Everything about superposition is related to the interference stuff he describes on page 31 of that paper you pink, where interference describes a statistical discrepancy between the system's indivisible dynamics and divisible (Markovian) ones.

 

[Sambuco]

That's what I said!

Ok, I misinterpreted what you said.

Nothing suggests the loss of factorization needs to involve some kind of non-local communication

I wasn't clear enough about this. What I mean is that the global change in the wavefunction/transition matrix is a nonlocal phenomenon. I wouldn't call it "communication". Of course, this is not a problem if the wavefunction/transition matrix is interpreted simply as information about the outcome of future events, given the outcome of past events. That is, conditional probabilities and nothing more.

You don't need collapse to do quantum mechanics as Many World proponents will vehemently tell you.

I know that! Personally, I prefer some $\Psi$-epistemic proposals, so I don't consider collapse to be physically real.

They don't.

Maybe I'm misrepresenting something. Suppose we have the state $\Psi_{A,B}(t) = \Psi_{A}^{\uparrow}(t) \otimes \Psi_{B}^{\downarrow}(t) - \Psi_{A}^{\downarrow}(t) \otimes \Psi_{B}^{\uparrow}(t)$. Now, if Alice measures $\uparrow$, the state of particle B becomes $\Psi_{B}^{\downarrow}$. Do you agree? Then, given the stochastic-quantum correspondence, the transition matrix should reflect this change in the wavefunction. We can interpret this epistemically, but the change is there. Am I right?

Q and R are correlated because their composite transition matrix remembers the initial locally induced correlation.

Well, my point is that this statement amounts to saying that the non-separable wavefunction remembers the locally-induced correlation. For a hidden-variables interpretation, it is usually a form of nonlocality.

Beyond these facts then its just talking about a deeper underlying interpretation which is not inherent to Barandes' formulation.

I agree

Lucas.

 

[Fra]

2) The unistochastic constraint on the transition matrix is something left to ponder on for me. it somehow is a constraint on the "predictive model" or its origin, or on the internal structure of the system (particle/agent). I have yet to think about this to find a deeper motivation for this (beyond correspondend), and the link to permutation matrices is indeed deeply interesting as permutation or scrambling is IMO indeed conceptually related to the most basic form of computation or action, scrambling, which is again ocnnecting to black holes as beeing thought of as t he optimal scramblers in nature. I think there is alot of food for thought there to think about, that may or many not lead to deeper progress. So can we understand computation, and emergent laws as somehow origitnating from som fundamental scrambling that gives emergence that looks nothing like scrambling from a macroperspective it will be interesting. This is why i enjoyed the conceptual connection to computing as well in one of the early youtube talks.

I was contemplating upon this yesterday and the positioning of Barandes correspondence in the bigger picture is getting a bit clearer I think.

First of all, Baranders noted that unistochastic process can usually be created from an embedding, if you at least have a bistochastic process; and bistochastic processes are not the most general, they are rather often associated to dynamics in equilibrium, or the timelessness that is characteristice of system dynamics or the newtonian schema. After the state evolution in Qm is deterministic - so nothing really happens! Once we know the initial conditions or boundary condititions, the future is "knonwn".

This appear closely related to the bistochastic constraint.

Barandes proved the correspondence with unistochastic(bistochastic via embedding) processes and a the hilbert picture of QM.

And as I looked at some toy models, of very general stochastic processing, they are certainly not even bistochastic in the general case! But bistochastic processes likely are related to "steady states" ir limiting cases of more general processes. Also related to why QM specifically works for small subsystems, and in cosmological perspectives, the framework itselt runs into deep touble. why?

If we use Baranders correspondec to think about the "problem" of hte QM side, but on the stochastic side the natural conclusion seems to be that it is related to deviations from biostochasticity, or even distributions.

In terms of biostochasticity from the perspective of a hypothetical "networks" of interacting "computing nodes", it seems to associate also to that the distribution of memory capacity is stationary. Which it would often be, on short time scales, but not in the evolutioanry perspective as memory might be gained or given up. And it seems there is a close analogy to energy density distribution. IF this is not stationary, we likely need more general stochastic models, and we need to "explain" during what conditions we get steady states which are bistochastic; and thus where QM or QFT are expected to hold; then it can be used via Baranders correspondence as a kind of "classical limit" - where by "classical" here i refer to normal QM/QFT - as opposed to the theory we still dont have.

But I think to move on with unification. We need also on the stochastic side, look for more genereal models that are NOT bistochastic.


/Fredrik

 

[PeterDonis]

If I synchronize two clocks so they are in time and corrrlated ans then bring them far apart ans then mess with one of them so they are no longer synchronized

Then you are doing something that can't violate the Bell inequalities. But measurements on entangled quantum systems can violate the Bell inequalities. So whatever is going on with entangled quantum systems, it can't be explained by the kind of simple local model you are implicitly using in your clock scenario.

 

[PeterDonis]

a measurement on one of the entangled particles constitutes a division event that restores factorization in the system

This statement is interpretation dependent; it's true only for interpretations where collapse is a physically real process. But you say in a later post that you prefer interpretations where it isn't. You can't have it both ways.

 

[iste]

Maybe I'm misrepresenting something. Suppose we have the state Ψ�,�(�)=Ψ�↑(�)⊗Ψ�↓(�)−Ψ�↓(�)⊗Ψ�↑(�). Now, if Alice measures ↑, the state of particle B becomes Ψ�↓. Do you agree? Then, given the stochastic-quantum correspondence, the transition matrix should reflect this change in the wavefunction. We can interpret this epistemically, but the change is there. Am I right?

No, because the wavefunction doesn't have to change like this for a description of a system using random variables to make sense. There is no requirement to use collapse for the physical picture to make sense. If you chose to do a conditioning exercise, that has nothing to do with the physical situation and is not required. Its something a statistician chooses to do.

According to Barandes: "Because the corresponding transition matrix ΓQR(t) encodes cumulative statistical effects starting at the initial time 0". The only other thing that happens apart from the loss of factorization is that the system dynamics divide / become ""momentarily divisible".

For a hidden-variables interpretation, it is usually a form of nonlocality.

Well all I am saying is that there is no explicit situation where there are influences that explicitly cause instantaneous changes to happen elsewhere in the paprts as of yet. There is a non-local correlation, sure, and it is ambiguous why that non-local correlation occurs; but then that requires additional interpretation beyond the theory, albeit we know so far that it results from a local interaction. The most one could gather I think is that presumably, any system with indivisible stochastic dynamics can evince these kinds of non-local correlations regardless of the exact mechanism that produces indivisible dynamics - you could have a local mechanism that would cause non-local correlations so long as there was indivisibility. So, essentially that is ambiguous, but there is no explicit kinds of non-local behaviors of the kind you have in Bohmian mechanics.

 

[iste]

Then you are doing something that can't violate the Bell inequalities. But measurements on entangled quantum systems can violate the Bell inequalities. So whatever is going on with entangled quantum systems, it can't be explained by the kind of simple local model you are implicitly using in your clock scenario.

I wasn't trying to explain Bell violations I was trying to convey the point that a loss of non-factorizability or loss of correlations between spatially distant things doesn't necessarily imply some kind of communication. You don't need communication to explain why clocks become unsynchronized. Presumably you don't need non-local communication to explain why correlations in an entanglement experiment might be degraded due to external noise.

 

[DrChinese]

... this measurement stops any causal influence between A and B for $t > t_1$.

...What Barandes proved is that QM formulated as a unistochastic process satisfies his new principle of "causal locality" which states that, if two localized systems remain spacelike separated during the time of a given physical process, they do not causally affect each other, in the sense that the conditional probabilities of one particle do not depend on what happens to the other.

His new principle of "causal locality" is absurd. Precisely the kind of mistake (i.e. assumption) EPR made.

EPR: They made their conclusion based on the ability to predict B after measuring A. They didn't look at the case of an A, B and C - which Bell showed was necessary.

Barandes: A & B are locally causal by his "new" and useless definition - which is why no one will ever need it for anything. It has long been known that a measurement on A does not affect the marginal probabilities of B. But the same is not true of measurement pairs on A & B and C & D (entanglement swapping, usually with 3 parties). With A(lice) & B(ob) remote, the marginal probability of their pairwise correlation is dependent on a remote swap operation by Victor. Causal locality is also not true for GHZ measurements (A, B and C by 3 parties).

The point is: If you define things so you cannot falsify your hypothesis, then you haven't accomplished anything. All Barandes' definition is good for is, in essence, stating that remote signaling is not possible. OK, everyone already agrees on this anyway.

Meanwhile: virtually everyone instead accepts the Bell definitions. That is why Bell is so important! It is easy to understand that a measurements on A and B are not separable (not in a Product state) as to their outcomes. Which they must be, if there is no mutual influence of some kind.

---

Furthermore: trying to cast Bell correlations in a statistical light is fundamentally flawed anyway. That is completely ignoring the entire lesson that EPR did successfully make: That ANY 1 individual measurement on A could lead to a perfect prediction for B. There is no marginal probability there. If the Barandes premise is that there is no connection (causal or otherwise!) whatsoever between A and B, then he has the problem of explaining how that perfect correlation arises - at any spin angle across 360 degrees! We're back to predetermination, and the Bell argument showing that there are no possible predetermined outcomes that are consistent with QM. There are no statistical averages to consider. A huge hole.

In other words: Barandes, as a scientist proposing a novel viewpoint, must subject his work to the most stringent of conditions and possible objections. He is giving himself a pass here, and so is anyone else who cannot address critiques on his position.

 

[DrChinese]

Presumably you don't need non-local communication to explain why correlations in an entanglement experiment might be degraded due to external noise.

"Communication"? A poor word choice, as it implies signaling.

"Degraded" correlations? Bell inequalities/correlations have been demonstrated to over a hundred SD. So who* is trying to bring noise into the equation, when it is obviously not theoretically relevant.


*And why...?

 

[lodbrok]

His new principle of "causal locality" is absurd.

Is this an emotional reaction, or is it based on something wrong with his definition? The definition is quite straightforward: https://arxiv.org/pdf/2402.16935

Causal influences should not be able to propagate faster than light.

What is absurd about this?

 

[PeterDonis]

I wasn't trying to explain Bell violations

Yes, and my point is that you need to if you are going to claim that your explanation is correct, because Bell inequality violations occur in nature. We've shown that with experiments. So any mental model you have that can't explain Bell inequality violations can't be right. And the mental models you suggested, like "how clocks become unsynchronized", can't explain Bell inequality violations. They satisfy the premises of Bell's Theorem. You need an explanation that violates at least one of those premises.

 

[iste]

Yes, and my point is that you need to if you are going to claim that your explanation is correct, because Bell inequality violations occur in nature. We've shown that with experiments. So any mental model you have that can't explain Bell inequality violations can't be right. And the mental models you suggested, like "how clocks become unsynchronized", can't explain Bell inequality violations. They satisfy the premises of Bell's Theorem. You need an explanation that violates at least one of those premises.

The comment was not putting forward a model or explanation of quantum mechanical behavior, it was trying to stimulate an intuition that if you have a non-factorizable but spatially separated system of any kind and disturb one of the parts so that it becomes factorizable, there is no logical necessity that the disturbance must be somehow causing some change at a spatially distant part. I could have literally used any example of any kind of behavior with no relation to quantum mechanics whatsoever. I could have used an example of people behaving in correlated ways and then one of them getting disturbed so that they are no longer correlated. You have misread what I was saying.

"Communication"? A poor word choice, as it implies signaling.

"Degraded" correlations? Bell inequalities/correlations have been demonstrated to over a hundred SD. So who* is trying to bring noise into the equation, when it is obviously not theoretically relevant.

See above.

 

[physika]

But lets suppose reality is emergent in some way,

Emergent from what ?
That "what" have to exist to give rise to that "reality"
Or that "what" simply is the real.

......

 

[PeterDonis]

The comment was not putting forward a model or explanation of quantum mechanical behavior

Yes, it was:

it was trying to stimulate an intuition that if you have a non-factorizable but spatially separated system of any kind and disturb one of the parts so that it becomes factorizable, there is no logical necessity that the disturbance must be somehow causing some change at a spatially distant part.

This is putting forward a model or explanation of quantum mechanical behavior.

If you seriously don't think that's the case, then what are you doing even posting in this thread? This thread is about a proposed interpretation of QM. Should I just delete all your posts as off topic and ban you from further posting in this thread?

 

[iste]

But the same is not true of measurement pairs on A & B and C & D (entanglement swapping, usually with 3 parties). With A(lice) & B(ob) remote, the marginal probability of their pairwise correlation is dependent on a remote swap operation by Victor. Causal locality is also not true for GHZ measurements (A, B and C by 3 parties).

I'm not sure this is true. I don't think any signalling across space is allowed so these phenomena cannot be about marginal probability distributions.

 

[iste]

Yes, it was:


This is putting forward a model or explanation of quantum mechanical behavior.

If you seriously don't think that's the case, then what are you doing even posting in this thread? This thread is about a proposed interpretation of QM. Should I just delete all your posts as off topic and ban you from further posting in this thread?

No, it isn't. If you read my conversation with Sambuco back to (or forward from) the initial comment (#604) he made that I replied to, you will see that the topic of the whole conversation is whether Barandes' formulation entails "nonlocal updating", in Sambuco's words. In other words, does measurement lead to a direct nonlocal change in the behavior of the system in Barandes' formulation. Sambuco was probing whether measurement leads to changes in the transition matrices or analogues of collapse which you would think of as some kind of nonlocal updating. We were both comparing to other kinds of formulations such as Bohmian mechanics where these things are explicit. Obviously there is something to be said for what collapse in QM means and whether it is relevant for Barandes' formulation. So you can see that we are having a discuasion probing whether different aspects of the formalism constitute aome kins of "nonlocal updating" and to what extent that could be interpreted physically. At I think post #665, Sambuco suggests that measurement-induced factorization should be considered "nonlocal updating" whoch is an interesting point. "Nonlocal updating" may be ambiguous. For instance, no-signalling or dependencies due to the quantun potential may be kind of transparently straightforward, but this may not be the case for everything. For instance; similar to what I mentioned in post #699, it can be ambiguous whether a correlation on its own across space entails some kind of non-local updating. Afterall, this can happen classically. Clearly that question may depend on other factors: e.g. does the correlation have a local common cause? Does the underlying microscopic deacription have some kind of non-local updating? etc, etc. Is a local explanation prima facie just seemingly implausible (e.g. like in the perfect spin case)? I think the loss of non-factorizability could possibly come under this kind of category where there is ambiguity; and in any case, I had never heard the loss of factorization being discussed as an instance of "nonlocal updating" before so I had no context that prescribes how to think of that. So I put forward my intuition that a loss of non-factorizability does not imply a kind of non-local updating, and there are many examples of analogies that you could say may support this intuition like the clock case. There doesn't seem to be anything further about the loss of factorization which would make these examples difficult - in contrast to, say, the bell spin correlations which have a unique structure which make them difficult to conceptualize in any other local sense. But where ia the uniaue structure in the loss of factorization that would analogously prohibt the use of auch analogies? In Barandes papers somewhere he refers to non-factorizability as a kind of "generic, model-independent" way of talking about interactions, and therefore correlations. So there seems to be nothing special in this description, and my intuition would be that the fact that entanglement correlations can get degraded due to external noise wouldn't be really an example of "non-local updating" either. It just seems to be a loss of correlation due to noise, which you don't need any extra-special mechanisms to explain, like in the clock case.

So hopefully you will see that my conversation with Sambuco has been a substantive, productive one about a genuinely relevant topic regarding whether "non-local updating" is a part of Barandes' formulation or not, ans the nuanced ambiguities that can occur in considering what can be seen as "non-local updating" and the use of thought provoking examples to argue for or against some point in which there is a standing ambiguity - is the loss of non-factorizability due to measurement an example "non-local updating"? I don't think it is, and as I said before in post #686, the loss of non-factorizability seems to actually be required to stop the measurement "non-locally updating", and coincides with Barandes' "no-signalling analogue result in the model.

 

[PeterDonis]

Thread closed for moderation.

 

[berkeman]

After a Mentor discussion, this long thread has run its course and will remain closed. Thanks to all who contributed.