Entaglement and hidden variables

[RUTA]

And all this does not depend at all on hidden variables.

But it does depend on superluminal information exchange, even in its Lorentz invariant manifestations. At least that's what they told me here at the Hiley Symposium this week.

 

[yoda jedi]

SQM - wf Collapse - Non Linear.

SQM - wf Collapse.
which one ? specific model please...

 

[zenith8]

At least that's what they told me here at the Hiley Symposium this week.

You mean Bohm's chief collaborator Hiley - I presume..
Anything interesting to report? New results? Gossip?

 

[Demystifier]

But it does depend on superluminal information exchange, even in its Lorentz invariant manifestations. At least that's what they told me here at the Hiley Symposium this week.

No, what I said IN THE POST ABOVE, does not depend on superluminal information exchange.

 

[Demystifier]

SQM - wf Collapse.
which one ? specific model please...

SQM - wf collapse, but no model
GRW, Penrose (or some other) specific model - no SQM

 

[yoda jedi]

SQM - wf collapse, but no model
GRW, Penrose (or some other) specific model - no SQM

i know, GRW (a CSL version, other versions: Adler, Pearle, Bassi, Diosi, Tumulka and others), Penrose, are objective collapse theories.
...And Singh, Elze, Svetlichny, Zloshchastiev, Hansson, Nattermann, Khrennikov and others are non linear but no standard -linear-.
but you said Standard Quantum Mechanics.

you mean SQM without collapse ?

 

[Demystifier]

you mean SQM without collapse ?

By SQM, I meant SQM with collapse, but without mathematical description of collapse in terms of a precise model. Instead, collapse is introduced as a vague postulate. Something like: "When a measurement is performed, the wave function collapses to an eigenstate of the measured observable."

 

[yoda jedi]

By SQM, I meant SQM with collapse, but without mathematical description of collapse in terms of a precise model. Instead, collapse is introduced as a vague postulate. Something like: "When a measurement is performed, the wave function collapses to an eigenstate of the measured observable."

and no model existent.

 

[Demystifier]

Fine, it works for one specific choice of the measured observable A only.

But then for another choice of the observable B (B not equal to A), I choose ANOTHER basis $$\varphi_b(x)$$, so instead of (40) now I can write
$$\psi(x,t) = \sum_b d_b(t) \varphi_b(x)$$
To measure B (rather than A) I have to apply a different interaction, so now (42) will no longer be true. Instead, with that different interaction, instead of (42) I will have
$$\Phi(x,z,t) = \sum_b d_b(t) \varphi_b(x) \xi_b(z)$$
This is different from (42). Yet, it has the same FORM as (42).

The physical point is that there is no measurement without interaction, and each kind of measurement requires a different kind of interaction. Consequently, each kind of measurement will lead to a different wave function. Yet, as long as each of these measuremts is "ideal", the wave function after the interaction always takes the FORM (42).

And all this does not depend at all on hidden variables.

The measurement I am talking here about is known also under the name non-demolition measurement:
http://en.wikipedia.org/wiki/Quantum_nondemolition_measurement