Exercise [21.14], p.522

deant · 02 Sep 2012, 18:10

I think Penrose has a minus sign in the wrong place here.

The first sentence of the exercise should read:

"Show that replacing $\psi$ by $x^1\psi$ or by $-i\hbar\partial\psi/\partial x^1$ corresponds, respectively, to replacing $\tilde{\psi}$ by $i\hbar\partial\tilde{\psi}/\partial p_1$ or by $p_1\tilde{\psi}$ ."

Note where the minus sign should be, and examine the posted solution to the exercise carefully!