Recent content by iste

Its not the quantum state at preparation but they are still evolving a quantum state backward in time from measurement. They are doing quantum theory backward-in-time. I have given various sources on this formulation in the original post. I mentioned in the previous post nd you'll find it in...

They are evolving a quantum state backward from the measurement. They are using quantum theory and just exploiting that it seems to work backward just as well as it works forward in time. The states using the backward evolution are just not necessarily the same as the ones forward in time, but...

I will give my take here on why it is not obvious that the backpropagation is "time-travel", connected to the fact that the quantum retrodiction is related to the normal forward-in-time usage by Bayes' rule. You can then infer the appropriate retrodictive probabilities using conventional...

I don't think so. Its related to Bayes' theorem about probabilities so I can't see this as making any presumption about determinism. As far as I can tell, the only retrodictive boundary required in these entanglement experiments in the conte t of the retrodiction as formulated in the papers is...

If it relies on information going backward-in-time, it doesn't rely on the other spatially separated measurement in a manner which is not mediated by the source. When I say local, I just mean about whether it is in conflict with relativity in the sense of requiring faster than light influence...

The description used in the papers is done exclusively with quantum theory, so I think what it comes down to is whether backward propagation is non-local. I think at least from the perspective of relativity, it is local. Local in some deeper sense depends on whether this backpropagation is...

Maybe, but I think that if this retrodiction is problematic, you have to ask why it seems to exist as an option in quantum theory in the first place that can be used in various applications as described in the papers of the original post. If they both to some extent already seems to exist in the...

I think it does though because the explanation only relies on a random measurement outcome and what that retrodicts backward-in-time in a manner which only really depends on that outcome. Well if Alice's photon is not telling Bob's photon what to do across space instantaneously, but instead...

Just realized that the first link I gave is not obviously accssible. One of these links has a straightforward pdf link. Section 4 has the relevant description which is more or less the same as the content in the researchgate link earlier...

The papers infer the correct Bell correlation in a manner that looks local, or doesn't require distamt communication in the.inference steps, only using quantum theory. How it does it is the retrodiction appears to violate statistical independence because as far as I can tell, evolving back from...

I meant it does the same in both cases once you measured the outcome and evolve back from it. The gist of the mechanism is you measure H, retrodict H back at the source. Retrodicting that a H photon was emitted implies another V photon was also emitted due to the atom description at source...

What I mean is that retrodicting back-in-time from the polarization measurement outcome always retrodicts the polarization state associated with that outcome. If you measure H, it retrodicts H back-in-time if the scenario was a measurement on a single-particle state. In the entanglement case...

Thats strange, it gives me as of now both the full article on the page and a pdf link. I can only offer a different link: https://scholar.google.co.uk/scholar?cluster=11813849258704424520&hl=en&as_sdt=0,5&as_vis=1 This is fair though my counter would be that: 1) for all intents and purposes...

These papers by Pegg et al. (doi: 10.1016/j.shpsb.2008.02.003 [section 4]; https://www.researchgate.net/publication/230928426_Retrodiction_in_quantum_optics [section 3.2]) seem to show that photon Bell correlations can be inferred using quantum theory in a manner that is compatible with locality...

Thought these papers might be relevant to realist perspective on Wogner friend: https://www.mdpi.com/1099-4300/24/7/903 Note how equation (12) and (34) is more or less the same as the kind of (in)divisibility condition you see in Barandes' papers...