3 papers
quant-ph2026
Gleason's Theorem for a Qubit as Part of a Composite System
Vincenzo Fiorentino, Stefan Weigert
We extend Gleason's theorem to the two-dimensional Hilbert space of a qubit by invoking the standard axiom that describes composite quantum systems. The tensor-product structure al…
quant-ph2026
A refined Frauchiger--Renner paradox based on strong contextuality
Laurens Walleghem, Rui Soares Barbosa, Matthew F. Pusey +1
The Frauchiger--Renner paradox derives an inconsistency when quantum theory is used to describe the use of itself, by means of a scenario where agents model other agents quantumly…
quant-ph2026
Beyond the Projection Postulate and Back: Quantum Theories with Generalised State-Update Rules
Vincenzo Fiorentino, Stefan Weigert
Are there consistent and physically reasonable alternatives to the projection postulate? Does it have unique properties compared with acceptable alternatives? We answer these quest…