Editing Consistent histories (section)

{{short description|Interpretation of quantum mechanics}}
{{Quantum mechanics|cTopic=[[Interpretation of quantum mechanics|Interpretations]]}}

In [[quantum mechanics]], the '''consistent histories''' or simply "consistent quantum theory"<ref name="Hohenberg-2010">{{Cite journal |last=Hohenberg |first=P. C. |date=2010-10-05 |title=Colloquium : An introduction to consistent quantum theory |url=https://link.aps.org/doi/10.1103/RevModPhys.82.2835 |journal=Reviews of Modern Physics |language=en |volume=82 |issue=4 |pages=2835–2844 |doi=10.1103/RevModPhys.82.2835 |issn=0034-6861|arxiv=0909.2359 }}</ref> [[Interpretation of quantum mechanics|interpretation]] generalizes the [[complementarity (physics)| complementarity]] aspect of the conventional [[Copenhagen interpretation]]. The approach is sometimes called  '''decoherent histories'''<ref name="aka-dh">{{cite web|last1=Griffiths|first1=Robert B.|title=The Consistent Histories Approach to Quantum Mechanics|url=http://plato.stanford.edu/entries/qm-consistent-histories/|website=Stanford Encyclopedia of Philosophy|publisher=Stanford University|access-date=2016-10-22}}</ref> and in other work decoherent histories are more specialized.<ref name="Hohenberg-2010"/>

First proposed by [[Robert Griffiths (physicist)|Robert Griffiths]] in 1984,<ref>{{cite journal | last=Griffiths | first=Robert B.|author-link=Robert Griffiths (physicist) | title=Consistent histories and the interpretation of quantum mechanics | journal=Journal of Statistical Physics | publisher=Springer Science and Business Media LLC | volume=36 | issue=1–2 | year=1984 | issn=0022-4715 | doi=10.1007/bf01015734 | pages=219–272| bibcode=1984JSP....36..219G| s2cid=119871795}}</ref><ref>{{Cite book |last=Griffiths |first=Robert B. |title=Consistent quantum theory |date=2003 |publisher=Cambridge Univ. Press |isbn=978-0-521-53929-6 |edition=First published in paperback |location=Cambridge}}</ref> this interpretation of quantum mechanics is based on a [[consistency]] criterion that then allows probabilities to be assigned to various alternative histories of a system such that the probabilities for each history obey the rules of classical probability while being consistent with the [[Schrödinger equation]]. In contrast to some interpretations of quantum mechanics, the framework does not include "[[Wave function collapse|wavefunction collapse]]" as a relevant description of any physical process, and emphasizes that measurement theory is not a fundamental ingredient of quantum mechanics. Consistent histories allows predictions related to the state of the universe needed for [[quantum cosmology]].<ref>{{cite journal | last1=Dowker | first1=Fay |author-link=Fay Dowker | last2=Kent | first2=Adrian | title=Properties of Consistent Histories | journal=Physical Review Letters | volume=75 | issue=17 | date=1995-10-23 | issn=0031-9007 | doi=10.1103/physrevlett.75.3038 | pages=3038–3041| pmid=10059479 | arxiv=gr-qc/9409037 | bibcode=1995PhRvL..75.3038D | s2cid=17359542 }}</ref>