Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Quantum Mechanics Equation Question

  1. Aug 9, 2011 #1
    I'm typing up my notes and I came across the attached equation and it seems I didn't write anything else about it; so, does it have a name or special classification?

    Attached Files:

  2. jcsd
  3. Aug 9, 2011 #2


    User Avatar
    Science Advisor
    Homework Helper

    It's no equation, it's an equality written incorrectly, because

    [tex] \frac{1}{r} \frac{\partial^2}{\partial r^2} r = 0 [/tex]
  4. Aug 9, 2011 #3
    But it's fine as an operator equality
    [tex]\frac{1}{r}\frac{\partial^2r\psi}{\partial r^2}=\frac{\partial^2\psi}{\partial r^2}+\frac{2}{r}\frac{\partial\psi}{\partial r}[/tex]
    Last edited: Aug 9, 2011
  5. Aug 9, 2011 #4
    If I remember correctly, this is the Laplacian in 2D, with azimuthal symmetry.

    Edit: No, I'm wrong. Perhaps it has something to do with the 3D wave equation. I definitely saw this in a PDE course.
    Last edited: Aug 9, 2011
  6. Aug 9, 2011 #5
    Operator equality and 3D wave equation both definitely fit with where it is in my notes!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook