🚀 go-pugleaf

jtwamley@physics.adelaide.edu.au (Jason Twamley) writes:

>braham@physics.ubc.ca (Stephen Braham) writes:

>>shouldn't be confused with the _dynamical_ collapse of the
>>wavefunction, induced by decoherence processes- that's a statement
>>on a Shroedinger picture density matrix, and ADH is a lot more
>>general than that.
>                                          ^^^^^^^^^^^^^^^^^^^^^^

>Hmmmm... I have head it said that ADH may be too restrictive for any
>system to match up to the Gell-Mann Hartle (GMH) criterion of quai-classical.
>Even Omnes believes that the GMH decoherence criterion is too tough...

Well, the definition of a quasiclassical domain is VERY strong, and
classicality is being redefined. I tend to lean towards the approximate
decoherence ideas, but that causes LOTS of problems (the statements
that Gell-Mann and Hartle make really do need EXTENSIVE improvement).
I'm presently spending time worrying about that, in fact. My biggest
worry is that you then seemed to be forced into needing an interpretation
of the off-diagonal elements in the decoherence functional. These
are NOT connected to the off-diagonal elements in the density matrix,
by the way- old-fashioned S-picture decoherence and ADH are produced
by similar effects (state squeezing, primarily), or so it seems, but
they are very different creatures in reality.


>Jason
		Steve

--
| Name: Stephen P. Braham | Perversion: Quantum Cosmologist|
| Hangout: UBC physics    | Signature:  Euclidean          |
|          Vancouver, BC  |--------------------------------+
|          Canada         | E-mail: braham@physics.ubc.ca  |