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 < > everyth...@googlegroups.com <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 everything-list+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/60be2bf7-31c9-4397-a61a-ca2c5908586a%40googlegroups.com.
