# Does the EPR experiment imply QM is incomplete?

• B
vanhees71
Science Advisor
Gold Member
2019 Award
That's already way better than Wikipedia, and that's how you indeed start to explain it when you start introducing QT, but it's not the final word. First of all, indeed the operators representing observables in QT have to be self-adjoint; Hermitean is not enough to guarantee the consistency of Born's rule. Another important point is that not the Hilbert-space vectors represent (pure) states but rays in Hilbert space (or more conveniently and equivalently by projection operators $|\Psi \rangle \langle \Psi|$, with $|\Psi \rangle$ normalized. Of course, the special case of entirely non-degenerate spectra to degenerate ones is also an important point but easily generalized.