How valid is the indivisible interpretation of quantum mechanics?

[gentzen]

From what I read the lack of causality is a feature and not a bug since it's supposed to break it and suggest that things happen randomly. Though I don't know how accurate that is.

Lack of "causal power" means something slightly different than lack of causality.

Lack of "causal power" occurs for example if trajectories in Bohmian mechanics are allowed to be discontinuous, but without specifying any rules for the discontinuities. Or rather, the only rule for the discontinuities is that the particle configuration after the jump must be still be distributed according to the quantum-equilibrium condition. But nothing is said about when or why jumps happen, whether only one particle can jump at a time, or only all particles can jump together.

As a consequence, knowing the current particle positions does not allow any predictions beyond those predictions already possible by knowing only the wavefunction. But intuitively, you still believe you can predict something, because if no jump occurs, then the normal Bohmian predictions would apply. And then you can get into discussions with Morbert that this is no problem, and you are demanding too much, when you want to know rules for those jumps.

 

[iste]

https://scholar.googleusercontent.c...textual+probability&hl=en&as_sdt=0,5&as_vis=1

A new Barandes preprint incase anyone interested.

 

[Matterwave]

Very noob question, and totally understand if the answer is "go read the paper", but to what level of detail has this "interpretation" been proven to give all the same results as QM?

Since it has a totally different mathematical formalism, it doesn't seem obvious to me how easy it is to prove "it's an interpretation" and not a new theory.

 

[gentzen]

Very noob question, and totally understand if the answer is "go read the paper", but to what level of detail has this "interpretation" been proven to give all the same results as QM?

I guess, the biggest contribution of Barandes' "interpretation" is that it shows just how difficult it is to convincingly "disprove" an interpretation, or at least to nicely explain why it feels really unsatisfactory (in its current form).

You might think that Copenhagen and Bohmian mechanics demonstrate this just as nicely. But people look for shortcuts and invent strawman's, like the instantaneous collapse of the wavefunction as a physical process, suppossedly postulated by Copenhagen, or the trouble of BM with Lorentz covariance. But that stuff is too easy, the challenge would be to explain the real deep flaws, like Barandes' discontinuous trajectories lacking any causal power.

Since it has a totally different mathematical formalism, it doesn't seem obvious to me how easy it is to prove "it's an interpretation" and not a new theory.

See https://www.physicsforums.com/threa...opic-theory-of-causality.1080105/post-7302909, especially

I probably asked one specific instance of those "continuity properties" even more explicitly somewhere, but that might not be overly important. It seems other people have at least started to provide that missing analysis:

... is a good find (another very recent one that may be of interest is arXiv:2602.22095).

I now read section "3 Short-time structure of the stochastic–quantum correspondence," which identifies a problem (for my specific instance) with differentiability.

I won't say "go read the paper," especially since I only read the first third of that paper. I guess it is a good paper, and I should read the other two thirds too, at some point in the distant future.

 

[Paul Colby]

Since it has a totally different mathematical formalism, it doesn't seem obvious to me how easy it is to prove "it's an interpretation" and not a new theory.

If it is a new theory, the authors clearly don't know either.

 

[Matterwave]

See https://www.physicsforums.com/threa...opic-theory-of-causality.1080105/post-7302909, especially

I won't say "go read the paper," especially since I only read the first third of that paper. I guess it is a good paper, and I should read the other two thirds too, at some point in the distant future.

I think this discussion is a little "above my pay grade". As I have not read the paper in detail, a lot of these arguments are going over my head haha. It seems I probably need to "go read the paper" to even have anything intelligent to say here.

 

[Matterwave]

If it is a new theory, the authors clearly don't know either.

Yeah I asked my question because, even in the case of Bohmian mechanics, even 60 years later and with "some decent subset of physicists working on it" there are still debates about whether it makes any predictions that are not congruous with QM (here's a recent one on whether arrival time experiments in BM might violate the no communication theorem: https://arxiv.org/abs/2409.04304v2 -- this paper says no but it's responding to other papers that say yes or "maybe").

So it would seem to me that such a new "interpretation" or "theory" as indivisible QM with such a different mathematical formalism would need more time to prove equality. But maybe the authors already did and my question is unwarranted.

 

[Paul Colby]

So it would seem to me that such a new "interpretation" or "theory" as indivisible QM with such a different mathematical formalism would need more time to prove equality.

Inequality with QM is by far the more interesting question. People definitely get benefits from reformulating a problem in different way. It potentially opens up new solutions and new ways of thinking about problems. As to this paper rendering QM more satisfactory to those perplexed by the topic, I don't see how it could. At the end of the day one needs to give something classical up or adopt something new nonclassical thing for QM systems to act like QM systems.

 

[Matterwave]

My knowledge on the topic, I must admit, come from like watching 2 YouTube videos of Barandeis describing the subject. (From the Robertson Podcast).

In one, he debates Tim Maudlin, and Tim's argument that this indivisible interpretation (Tim would certainly call this a theory and not an interpretation but we don't need to get into that here lol) constitutes "spooky action at a time" (instead of spooky action at a distance lol) and that this interpretation precludes our ability to "screen off" probabilities from any time in the past (i.e. we need the entire history of the universe to make any predictions, not just the entire state of the universe at a given time) convinced me that yeah this interpretation is just as weird as the rest of them. So, from an interpretive point of view, it's maybe not any better than BM's gross non locality, or Superdeterminisms assault on scientific predictability (does A/B testing still make sense if we can't randomize anything? Maybe, but it makes it harder to justify conceptually at least.).

If indivisible non-markov processes make new predictions though, that would be interesting.

 

[Matterwave]

Link to the video for those interested

 

[Sambuco]

Very noob question, and totally understand if the answer is "go read the paper", but to what level of detail has this "interpretation" been proven to give all the same results as QM?

Since it has a totally different mathematical formalism, it doesn't seem obvious to me how easy it is to prove "it's an interpretation" and not a new theory.

If you're interested in reading about the indivisible interpretation, it might be best to start with one of the earlier works. The proof of the theorem is here, although I think this is the clearest work regarding the interpretation.

In one, he debates Tim Maudlin, and Tim's argument that this indivisible interpretation (Tim would certainly call this a theory and not an interpretation but we don't need to get into that here lol) constitutes "spooky action at a time"

Regarding locality, Barandes addresses the issue in a separate paper. With regard to what Tim Maudlin pointed out, Barandes explicitly states, in this other work: "One can view non-Markovianity roughly as a form of non-locality in time that is consistent with the light-cone structure of special relativity."

I hope I was able to help you!

Lucas.