Relativity of quantum states and observables

Paul Busch, Leon Deryck Loveridge, Takayuki Miyadera

Research output: Contribution to journalArticlepeer-review


Under the principle that quantum mechanical observables are invariant under relevant symmetry transformations, we explore how the usual, non-invariant quantities may capture measurement statistics. Using a relativisation mapping, viewed as the incorporation of a quantum reference frame, we show that the usual quantum description approximates the relative one precisely when the reference system admits an appropriate localisable quantity and a localised state. From this follows a new perspective on the nature and reality of quantum superpositions and optical coherence.
Original languageEnglish
Article number40004
Number of pages5
JournalEPL (Europhysics Letters)
Early online date4 Apr 2017
Publication statusE-pub ahead of print - 4 Apr 2017

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© EPLA, 2017. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details


  • quantum mechanics
  • symmetry
  • quantum reference frames

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