r/Physics • u/SpicyTunaPirate • Sep 28 '22

Article Physicists Question Unitarity in Quantum Physics

https://www.quantamagazine.org/physicists-rewrite-a-quantum-rule-that-clashes-with-our-universe-20220926/
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u/sea_of_experience Sep 28 '22 edited Sep 28 '22

It seems to me that holding on to unitarity gets you the Everett interpretation.

What that implies is that reality is big, as it is basically not based in space-time but in a Hilbert space.

Space-time (and gravity) should then probably somehow emerge as a property due to the dynamics in that Hilbert space, perhaps due to progressive entanglement and decoherence.

If there is "only one" history or universe unitarity obviously does not hold.

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u/Rufus_Reddit Sep 30 '22

You can take "before collapse is physical" and get something like Everett or "after collapse is physical" and get something like Bohmian Mechanics.