TITLE: What is the relationship between spherical harmonics and the schrodinger equation?
QUESTION [8 upvotes]: spherical harmonics (below image)  
 
Schrödinger equation(below image)

What is the relationship between spherical harmonics and the schrodinger equation?

REPLY [6 votes]: The Schrödinger equation, and in particular the Schrödinger equation with $1/r$ electric potential function, is not something that you can "derive" from mathematics.  Mathematically it would be perfectly consistent for  photons to be massive (which would result in a Yukawa potential rather than $1/r$).