> On 18 Sep 2019, at 12:22, Philip Thrift <[email protected]> wrote: > > > > On Tuesday, September 17, 2019 at 11:46:35 PM UTC-5, Bruce wrote: > On Wed, Sep 18, 2019 at 10:37 AM 'Brent Meeker' via Everything List > <[email protected] <javascript:>> wrote: > On 9/17/2019 3:49 PM, Bruce Kellett wrote: >> On Wed, Sep 18, 2019 at 3:01 AM smitra <[email protected] <javascript:>> >> wrote: >> On 17-09-2019 13:32, Bruce Kellett wrote: >> > >> > So why do all Everettians have to add so many additional assumptions >> > in order to pretend to get out the Born rule? >> > >> >> Simply assuming the special case of the Born rule that measuring a >> system in an eigenstate of an observable will yield the eigenvalue of >> that eigenstate with certainty, is enough. >> >> Where did the concept of an observable as an operator in a Hilbert space, >> and the idea that measurements correspond to the action of that observable >> on the state, giving a result that is the eigenvalue corresponding to the >> projected eigenvector, come from? > > The operator should be expressible in terms of the Hamiltonian of the > measuring instrument and its interaction with the system. But nobody tries > to write down the Hamiltonian of the instrument; they just look at what it's > supposed to measure classically and then they write an abstract operator that > does that. > > So it is something added to the supposed "minimal QM" of the Schrodinger > equation. The eigenvector/eigenvalue link is pretty well established. Zurek > has a good argument to derive this. > > Bruce > > > > The Zurek (QD) theory is a very good (in my view) framework to consider. A > useful antidote to MWI. > > https://arxiv.org/abs/1807.02092 <https://arxiv.org/abs/1807.02092> > > Quantum Theory of the Classical: Quantum Jumps, Born's Rule, and Objective > Classical Reality via Quantum Darwinism > > Wojciech Hubert Zurek > (Submitted on 5 Jul 2018) > > Emergence of the classical world from the quantum substrate of our Universe > is a long-standing conundrum. I describe three insights into the transition > from quantum to classical that are based on the recognition of the role of > the environment. I begin with derivation of preferred sets of states that > help define what exists - our everyday classical reality. They emerge as a > result of breaking of the unitary symmetry of the Hilbert space which happens > when the unitarity of quantum evolutions encounters nonlinearities inherent > in the process of amplification - of replicating information. This derivation > is accomplished without the usual tools of decoherence, and accounts for the > appearance of quantum jumps and emergence of preferred pointer states > consistent with those obtained via environment-induced superselection, or > einselection. Pointer states obtained this way determine what can happen - > define events - without appealing to Born's rule for probabilities. > Therefore, Born's rule can be now deduced from the entanglement-assisted > invariance, or envariance - a symmetry of entangled quantum states. With > probabilities at hand one also gains new insights into foundations of quantum > statistical physics. Moreover, one can now analyze information flows > responsible for decoherence. These information flows explain how perception > of objective classical reality arises from the quantum substrate: Effective > amplification they represent accounts for the objective existence of the > einselected states of macroscopic quantum systems through the redundancy of > pointer state records in their environment - through quantum Darwinism.
That is meaningful …. only in the MW. Bruno > > > > @philipthrift > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/ee4aa20d-b9bd-407b-b985-3ab107e0f7b2%40googlegroups.com > > <https://groups.google.com/d/msgid/everything-list/ee4aa20d-b9bd-407b-b985-3ab107e0f7b2%40googlegroups.com?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/4B2ED6EF-99BD-44B0-9805-D8038A4FD49E%40ulb.ac.be.
