- #1
Jacob Nie
- 9
- 4
- Homework Statement
- The section is about the probability of obtaining a certain ##\omega## upon measurement of operator ##\Omega.## And here it is dealing specifically with the case of a degenerate ##\Omega.##
It says: In general, one can replace in Postulate III
$$P(\omega)\propto \langle \psi | \mathbb{P}_{\omega}|\psi\rangle $$
where ##\mathbb{P}_{\omega}## is the projection operator for the eigenspace with eigenvalue ##\omega.##
(Postulate III was ##P(\omega)\propto |\langle \omega | \psi \rangle |^2.##)
- Relevant Equations
- n/a
I don't see why it is not ##P(\omega)\propto |\langle \psi | \mathbb{P}_{\omega}|\psi\rangle |^2.## After all, the wavefunction ends up collapsing from ##|\psi\rangle## to ##\mathbb{P}_{\omega}|\psi\rangle.##