Is MWI Compatible with a Deterministic Interpretation of Decoherence?

[kof9595995]

Just read a bit about decoherence from wiki, it seems to me that according to this interpretation, the probabilistic nature of QM is no different from statistical mechanics, and the irreversibility of measurement is just thermodynamic, so does this mean decoherence is indeed a deterministic interpretation?

 

[Demystifier]

First of all, decoherence is not an interpretation, but an experimental fact. Theoretically, it is a direct consequence of the Schrodinger equation applied to a large number of degrees of freedom.

Decoherence is a deterministic process, in which probability evolves deterministically. In this process quantum probabilistic laws effectively evolve towards classical ones, thus explaining why, on the macroscopic level, for all practical purposes we can use classical statistical mechanics. More precisely, decoherence provides a continuous deterministic mechanism by which the interference terms in the probability density become dynamically suppressed.

Decoherence also plays an important role in some interpretations of QM, especially many-world and Bohmian. But these interpretations (controversial just as all other interpretations) should be distinguished from decoherence itself which is not controversial at all.

 

[kof9595995]

Is it correct to say interpretations of QM are mainly concerned with measurements? So does it mean decoherence is not the whole story of measurements? If so, what cannot be explained by decoherence? Sorry for shooting a lot of questions at the same time : )

 

[JK423]

More precisely, decoherence provides a continuous deterministic mechanism by which the interference terms in the probability density become dynamically suppressed.

It's deterministic in what sense? The interference terms do get suppressed by known procedures making a, initially pure, state mixed. But decoherence cannot tell you the specific state that the system will end up to. Right?

 

[Demystifier]

It's deterministic in what sense? The interference terms do get suppressed by known procedures making a, initially pure, state mixed. But decoherence cannot tell you the specific state that the system will end up to. Right?

Right. It is a deterministic evolution of the probability density, so probabilistic interpretation is not removed (unless you adopt a many-world or Bohmian interpretation).

 

[Demystifier]

Is it correct to say interpretations of QM are mainly concerned with measurements?

Yes.

I
So does it mean decoherence is not the whole story of measurements?

True.

If so, what cannot be explained by decoherence?

Why and how the system takes only one of the possibilities (defined by the decohered density matrix).

 

[kof9595995]

Thanks.

 

[yoda jedi]

If so, what cannot be explained by decoherence?

need be supplemented with MWI.
to takes only one of the possibilities.