Aharonov-Albert-Vaidman weak values — pointer shift beyond eigenvalue range
The Aharonov-Albert-Vaidman (1988) weak value A_w = ⟨f|A|i⟩/⟨f|i⟩ can be complex and far outside the eigenvalue spectrum. The pointer shifts by Re(A_w) in position and Im(A_w) in momentum. Post-selection on a nearly orthogonal final state amplifies weak signals at the cost of discarding most trials. Spin-½ eigenvalues are ±1, but Re(A_w) can reach ±100 for near-orthogonal pre/post states.