On Friday, November 22, 2019 at 11:59:41 PM UTC-6, Brent wrote: > > > > On 11/22/2019 9:35 PM, Bruce Kellett wrote: > > On Sat, Nov 23, 2019 at 7:02 AM 'Brent Meeker' via Everything List < > [email protected] <javascript:>> wrote: > >> On 11/22/2019 6:14 AM, John Clark wrote: >> >> Why does the act of measurement seem to override the evolution of >> Schrödinger's wave function, and what exactly does a "measurement" even >> mean? Many Worlds is the only interpretation that can give a credible >> answer to that question >> >> >> The epistemological interpretation also gives a credible answer. >> > > Have you ever seen the paper by Pusey, Barrett, and Rudolph > (arXiv:1111.3328)? They prove a theorem that places limitations on the > viability of a purely epistemic interpretation of the wave function: "Here > we show that any model in which a quantum state represents mere information > about an underlying physical state of the system, and in which systems > prepared independently have independent physical states, must make > predictions which contradict those of quantum theory." > > > Which continues: > > "The argument depends on few assumptions. One is that a > system has a “real physical state” – not necessarily com- > pletely described by quantum theory, but objective and > independent of the observer. This assumption only needs > to hold for systems that are isolated, and not entangled > with other systems. Nonetheless, this assumption, or > some part of it, would be denied by instrumentalist ap- > proaches to quantum theory, wherein the quantum state > is merely a calculational tool for making predictions con- > cerning macroscopic measurement outcomes." > > There is also this paper, which discusses some loopholes the the > assumptions of the PBR theorem: > > Implications of the Pusey-Barrett-Rudolph quantum no-go theorem > Maximilian Schlosshauer, Arthur Fine > (Submitted on 21 Mar 2012 (v1), last revised 27 Jun 2012 (this version, > v3)) > Pusey, Barrett, and Rudolph introduce a new no-go theorem for > hidden-variables models of quantum theory. We make precise the class of > models targeted and construct equivalent models that evade the theorem. The > theorem requires assumptions for models of composite systems, which we > examine, determining "compactness" as the weakest assumption needed. On > that basis, we demonstrate results of the Bell-Kochen-Specker theorem. > Given compactness and the relevant class of models, the theorem can be seen > as showing that some measurements on composite systems must have built-in > inefficiencies, complicating its testing. > Comments: 4 pages. v2: tweaked presentation, new title; v3: minuscule > edits to match published version > Subjects: Quantum Physics (quant-ph) > Journal reference: Phys. Rev. Lett. 108, 260404 (2012) > DOI: 10.1103/PhysRevLett.108.260404 > Cite as: arXiv:1203.4779 [quant-ph] > (or arXiv:1203.4779v3 [quant-ph] for this version) > > > Brent >
*Epistemic interpretations of quantum theory have a measurement problem* Quantum Physics and Logic 2019 - https://qpl2019.org/ https://qpl2019.org/wp-content/uploads/2019/05/QPL_2019_paper_2.pdf *We have demonstrated that state update under measurement poses a serious challenge to ψ-epistemic interpretations of quantum theory in the ontological models framework: all currently known ψ-epistemic models for full quantum theory in d ≥ 3 cannot faithfully represent* *state update. This runs in direct contrast to the prevailing view that ψ-epistemic models provide a compelling explanation of state update.* @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]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/60be2bf7-31c9-4397-a61a-ca2c5908586a%40googlegroups.com.
