Entanglement swapping and Bohmian mechanics

[martinbn]

If you have a |V> photon stream (say from a laser) that you can only measure on the $\{|+\rangle, |-\rangle\}$ basis, yes, that is meaningful.

No, I meant what I said. You have a qubit (the physical realisation is not important, but if you like you can think of it as polarization of photons), and you can measure in both basis.

I would not call them the same state though. Naturally, I can distinguish them experimentally using a suitably oriented PBS.

Similarly, I can distinguish the difference between Ma's (1) and (2) experimentally. As they do. Megidish as well. Disagree?

Yes, it is exactly the same as in Ma's paper, just a simpler case, no swapping involved, so that the trees are not in the way to see the woods. And, yes, I disagree. On this you are wrong! It is very basic, your confusion is not even in the basic QM. It is much simpler it is writing the same vector in two different basis. But all this has been said many times. It is your job to clear this for yourself. Untill then you will not understand Ma's paper.

 

[martinbn]

In the actual experiments, it is not done as you describe/imagine at all.

I know. My point was to consider what I described instead of the actual experiment.

So... no. Of course the selection process does not create entanglement. It is the physical overlap, and nothing else, that varies. No more than a post-selection filter causes cancer (or the appearance thereof) in medical studies.

But your use of the word entanglement is prisicely that. You said it yourself in the other thread, entanglement = non-classical correlations. Why is there no entanglement in this case (the one that I described, not the actual experiment)?

 

[Morbert]

Sure.

Great. So do you accept Huggett when he says (1.3), decomposed using the Bell basis, is (1.4)?

 

[Demystifier]

John Cramer's transactional interpretation is NOT an interpretation. It is not a theory either. It is a story or a narrative, intended as a complement to Copenhagen.

I'm glad that someone pointed this out explicitly.

 

[DrChinese]

Suppose that in the swap set up, nothing is done to photons 2 and 3. But the usual measurments are done on 1 and 4. This goes for all the runs. Then in the data of the results of the measurements on 1 and 4 you can find a subset of runs which show non-classical correlations. According to you that would mean that post-selection can create entanglement just as the swap can. Right?

In your particular example, since you asked again in #512:

No, there are certainly no identifiable fourfold coincidence subsets featuring non-classical correlations. Unless of course, you plan to cherry pick by hand.

No ticket, no laundry. There must be physical overlap for entanglement and non classical correlations.

 

[martinbn]

In your particular example, since you asked again in #512:

No, there are certainly no identifiable fourfold coincidence subsets featuring non-classical correlations. Unless of course, you plan to cherry pick by hand.

Yes, I search through the data and find such a subset of runs. I don't even have to do it, we know there is suh subset. The point is that it will show non classical corelations, and for you that means entanglembent.