Recent content by Morbert

No. The operationalis/instrumentalist account is probabilistic and has no objective collapse. Consistent histories is probabilistic and has no objective collapse. Recent nonmarkovian reformulations are probabilistic and have no objective collapse.

I still need to read the paper properly to give a proper response, but in the AOE section they have "ii. P(a|cd,...)" and "iii. P(b|cd,...)". Since c and d are on the righ hand side of the |, I read these as sparse directed conditional probabilities, conditioned at the time when Charlie and...

I'm not sure what you mean by this but I don't think I agree, and it would take us too far into philosophy for my comfort.

The only relevance systems that partition into a measured system and a measurement device/environment have is they are the systems we are typically interested in. The formalism can be applied in principle to the universe as a whole, or to a single isolated hydrogen atom, never to be measured...

Remember though that in this formalism, the configuration a system or subsystem is in is not indexed to any observer. In which case if the above is a rejection of AOE, then this formalism does not reject AOE.

I don't see how the bit in bold is true if dynamics are non-Markovian. [edit] - I.e.: AOE + Markovian dynamics = joint probability exists no AOE + Markovian dynamics = joint probability doesn't exist AOE + non-Markovian dynamics = joint probability doesn't exist It's not too important. At...

@Sambuco Re/ Wigner's friend:

I am not sure what GSC is. Do you mean GSS (generalized stochastic system)? What Barandes shows is that we can associate any quantum system with a stochastic process unfolding on a classical configuration space of arrangements, and dynamics given by stochastic maps, allowing us to conceptualize...

This stochastic formalism rejects everywhere-divisible dynamics, something Bong et al don't consider. This is perfectly reasonable, given how new this stochastic approach is. But ultimately we can have a conditional probability fail to obtain while any observed event is still "a real single...

Honestly, I'm not, as it is what connects a mathematical result to a physical interpretation. It's what lets you regard a quantum system as a generalized stochastic system with dynamical laws and a microphysical ontology. But I have explained that many times by now.

@iste One reason this discussion has gone on for so long is I wasn't sure I fully understood your concern. But now I'm pretty sure I do, and so I will start to wind down the conversation on my end unless some new aspect not previously articulated is brought up.

Barandes does indeed observe in arXiv:2309.03085 that a stochastic process ##(\chi,\mathcal{T},p,\mathcal{A})## is more general than a generalized stochastic system ##(\mathcal{C},\mathcal{T},\Gamma, p, \mathcal{A})##. But the correspondence he investigates is between generalized stochastic...

I will have to admit my knowledge of the LF no-go theorem is minimal, so my response will be from the hip. From the paper: The transition map used by Alice and Bob will not have a division event at Charlie's and Debbie's measurement, and so no such joint probability distribution can be...

To clarify, I understand "take something like spin and translate it into a generalized stochastic process" in two ways. i) Translate it to a general stochastic system with a configuration space directly constructed from spin labels and ii) Construct a general stochastic system that reproduces...

I would like to hone in on this for a moment: Barandes presents a model of a generalized stochastic system as a tuple of the form ##(\mathcal{C},\mathcal{T},\Gamma,p,\mathcal{A})## where ##\mathcal{C}## is the configuration space. Is your objection that ##\mathcal{C}## is not selected by the...