- #1

- 12

- 0

**1. Let G be an operator on H (Hilbert Space). Show that:**

(a) H = 1/2 (G + G[tex]^{\dagger}[/tex]) is Hermitian.

(b) K = -1/2 (G - G[tex]^{\dagger}[/tex]) is Hermitian.

(c) G = H + iK.

(a) H = 1/2 (G + G[tex]^{\dagger}[/tex]) is Hermitian.

(b) K = -1/2 (G - G[tex]^{\dagger}[/tex]) is Hermitian.

(c) G = H + iK

## Homework Equations

...

**3. The Attempt at a Solution :**

(a) Since the adjoint of the sum of two operators does not change their position (addition of operators is commutative), it is very straight forward.

(b) This is where I run into trouble, and I think it is because the problem is wrong. The operator given appears to be anti-hermitian (skew-hermitian), however I would like confirmation. This result makes (c) very difficult, as it uses an incorrect answer. My suspicion is that the intended question includes an i (as in, H = -i/2 (...)):

K[tex]^{\dagger}[/tex] = -1/2 (G[tex]^{\dagger}[/tex] - G) = 1/2 (G - G[tex]^{\dagger}[/tex]) = -K.

(c) Well if I am correct about (b), (c) is wrong. I was just hoping someone could confirm I am right, or show me how K is Hermitian. I can take it from there.