Recent content by Sambuco

Yes, this is really very relevant! In section 4.1, it says: "Then, in Equation (3) of [9], it implicitly assumes ##p(abcd|xy) = p(ab|cdxy) p(cd|xy)##. Together, they imply ##p(ab|xy) =\sum_{c,d} p(ab|cdxy) p(cd|xy)##. However, as discussed in Section 2, the law of total probability does not...

That's true, but cases ii and iii correspond to situations where Alice and Bob enter their respective laboratories and ask Charlie and Debbie for their measurement outcomes. In other words, these are cases where Alice and Bob do not erase Charlie and Debbie's measurement results. Lucas.

Thanks for the reference. Barandes is pretty clear about that. I was trying to understand at what exact point Bong et al. assume a Markovian dynamics. In eq. (3), they write ##P(ab|xy) = \sum_{c,d} {P(abcd|xy)} = \sum_{c,d} {P(ab|cdxy) P(cd)} ##. In the first equality, they assume AOE, while in...

I think this is what it means to reject absoluteness of observed events. Lucas.

We were talking about the case of Wigner's friend thought experiments, where a superobserver makes measurements that, in principle, give rise to interference between quasiclassical branches. Lucas.

There's an error preventing me from playing the video from here. Were you pointing out a specific moment? Lucas.

I'm not sure I understand what you're trying to say here. I think this contradicts something mentioned in Bong's article: "the assumption of AOE implies that, in each run of the experiment (...) there exists a well-defined value for the outcome observed by each observer, that is, for a, b, c...

Yes, that's the point! So Barandes' interpretation addresses LF no-go theorem by rejecting AOE. I think AOE implies something more radical. If a joint probability distribution cannot be constructed from the perspectives of Alice and Bob, then Charlie and Debbie's measurements are only events...

To a certain extent, Bohmian mechanics is a typical realist interpretation. There is a clear distinction between the variables that represent the physical state of a system and the way in which probabilities arise as a result of the impossibility of knowing that complete description. Barandes'...

I'm not sure that the epistemic nature of probabilities leads to AOE. For example, relational quantum mechanics assumes that probabilities are epistemic, but denies AOE. Anyway, let's assume you're right and Barandes' formulation/interpretation does not violate AOE, then how does the...

I think Barandes's formulation is not limited to the stochastic-quantum correspondence but also incorporates (classical) configuration space as the ontology of the model. If we consider his work as starting from quantum mechanics and arriving at indivisible stochastic processes, I fully agree...

Thanks @Fra for these references. I'll check them out! :smile: Lucas.

Yes, it's a different notion of locality. "Causal locality" as defined in section VII of Barandes' paper means that, for a system composed of two parts that remain spacelike-separated (no local interaction), conditional probabilities factorize. In Cavalcanti's work, locality is equivalent to...

There are some interesting papers ("Quantum theory from rules on information acquisition" and Quantum theory from questions) that derive quantum mechanics from principles closely related to Rovelli's formulation. However, they do not go beyond a reconstruction of the formalism. Lucas.

That's possible. However, absoluteness of observed events is closely related to a certain kind of relationality, and Barandes says: "This interpretation has a thoroughly realist orientation, and does not entail parallel universes, nor does it involve perspectival or relational notions of...