Fourier transform. Impulse representation.

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 1K views
LagrangeEuler
Messages
711
Reaction score
22
##\varphi(p)=\frac{1}{\sqrt{2\pi\hbar}}\int^{\infty}_{-\infty}dx\psi(x)e^{-\frac{ipx}{\hbar}}##. This ##\hbar## looks strange here for me. Does it holds identity
##\int^{\infty}_{-\infty}|\varphi(p)|^2dp=\int^{\infty}_{-\infty}|\psi(x)|^2dx=1##?
I'm don't think so because this ##\hbar##. So state in impulse space is not normalized.
 
Physics news on Phys.org
LagrangeEuler said:
Does it holds identity
##\int^{\infty}_{-\infty}|\varphi(p)|^2dp=\int^{\infty}_{-\infty}|\psi(x)|^2dx=1##?

Yes, it does. The ##\hbar## in the transform is required in order to make this true. You may be thinking of the standard Fourier transform:
$$A(k) = \frac{1}{\sqrt{2\pi}}\int_{-\infty}^{+\infty}{\psi(x)e^{-ikx}dx}$$
Changing variables from k to ##p = \hbar k## introduces the extra ##\hbar## in the constant factor.