Amplitude of a space wave function

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

Zinc Potterman - 20 Apr 2006 09:34 GMT

My physics book gives an example of a space wave function (at steady state)
as:

psi(r) = A (exp[-ikr] + bexp[ikr])/r (1)

In the text it assumes that A is real, by stating that:

|A|^2 is positive.

This assumption seems unreasonable to me.

Is there any reason why in equation (1) A can't be imaginary?
Maybe the fact that it reperesents a function necessitates realness?
Any thoughts would be appreciated
Zinc

Signature

zincnews at tiscali.co.uk
To reply to address don't click.
Cut and paste, change at to @ symbol
then delete spaces.
------------------------------------

Reply to this Message

PD - 20 Apr 2006 15:40 GMT

> My physics book gives an example of a space wave function (at steady state)
> as:
[quoted text clipped - 8 lines]
>
> Is there any reason why in equation (1) A can't be imaginary?

It can. Note that this is completely equivalent to adding a phase to
the argument of the exponential, and so doesn't really add anything.

Change psi(r) to C(exp[-ikr]+b*exp[ikr])/r, where C = A + iB, now
complex. Now do a little algebra to show that
psi(r) = A(exp[-ikr + f] + b'*exp[ikr + f])/r, with b' a constant in
terms of b and B, and f a constant in terms of B.

PD

> Maybe the fact that it reperesents a function necessitates realness?
> Any thoughts would be appreciated
[quoted text clipped - 6 lines]
> then delete spaces.
> ------------------------------------

Reply to this Message

Natural Science Forum / Physics / Particle Physics / April 2006

Amplitude of a space wave function