Philosophy of Physics Seminar (Thursday - Week 2, HT25)

Abstract: In a recent trend of research, it has been clarified that what von Neumann’s so-called ‘impossibility proof’ really proves is that quantum hidden variables theories with deterministic states cannot represent properties using Hermitian operators. On the other hand, the analysis of representation of measurement in Hilbert space shows that in these theories Hermitian operators map experimental interactions to eigenvalues. These two features imply that contextuality does not affect quantum properties, but, quite naturally, interactions between target systems and measuring devices. On this basis, I show—without invoking (the violation of) Bell inequalities—that theorems connecting contextuality to nonlocality show that hidden variables theories with deterministic states must violate parameter independence.