Boundary terms in hilbert space goes vanish

[notojosh]

Thant helped. thank you!

 

[Fredrik]

Can you give a more exact reference? A link to the exact page at google books would be the best way to reference it.

I assume it has something to do with the common claim that square integrable functions must go to zero as the variable goes to infinity ($\psi(x)\rightarrow 0$ when $x\rightarrow\infty$), which is actually wrong. (There are counterexamples. See this thread). However, I think $\psi(x)$ must go to zero as x goes to infinity if $Q\psi$ (where Q is the position operator) is square integrable. Maybe it also has to go to zero if $P\psi$ (where P is the momentum operator) is square integrable? (I don't have time to think that through right now).