hokhani
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- TL;DR
- The correctness of an equation for antilinear operators
An antilinear operator ##\hat{A}## can be considered as, ##\hat{A}=\hat{L}\hat{K}##, where ##\hat{L}## is a linear operator and ##\hat{K} c=c^*## (##c## is a complex number). In the Eq. (26) of the text https://bohr.physics.berkeley.edu/classes/221/notes/timerev.pdf the equality ##(\langle \phi |\hat{A})|\psi \rangle=[ \langle \phi|(\hat{A}|\psi \rangle)]^*## is given but I think this equation is not correct within a minus sign. For example, in the Hilbert space of spin up and down, having ##\hat{L}=\hat{\sigma_y}## and ##|\psi\rangle=\psi_1 |+\rangle +\psi_2 |-\rangle## and ##|\phi\rangle=\phi_1 |+\rangle +\phi_2 |-\rangle## we have: ##\langle \phi | (\hat{A} |\psi\rangle)=-i\phi_1^* \psi_2^*+i\phi_2^*\psi_1^*## and ##(\langle \phi|\hat{A})|\psi \rangle=i\phi_2 \psi_1 -i\phi_1 \psi_2## which gives ##(\langle \phi |\hat{A})|\psi \rangle=-[ \langle \phi|(\hat{A}|\psi \rangle)]^*##. I appreciate any help.
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