- #1

- 117

- 13

## Main Question or Discussion Point

Take a projection operatorP

However if the ket of m is a column matrix of m x 1 and its bra the complex conjugate with 1 x m length

therefore <m|m> = |m|

since the m here is the same since projection operator is the same.

if A is a matrix

B = A

A*B=B*A

but P

but this makes no sense as |m|

Can anyone explain?

_{m}=|m><m|However if the ket of m is a column matrix of m x 1 and its bra the complex conjugate with 1 x m length

therefore <m|m> = |m|

^{2}since the m here is the same since projection operator is the same.

if A is a matrix

B = A

A*B=B*A

but P

_{m}*P_{m}= P_{m}(Projection operator)but this makes no sense as |m|

^{2}*|m|^{2}= |m|^{4}Can anyone explain?

Last edited: