The Kepler Problem (Part 7)

I’ve explained a cool way to treat bound states of the hydrogen atom as wavefunctions on a sphere in 4-dimensional space. But so far I’ve been neglecting the electron’s spin. Now let’s throw that in too!

This will wind up leading us in some surprising directions. So far I’ve just been reviewing known ideas, but now we’re getting into my new paper:

• Second quantization for the Kepler problem.

It starts out being quite routine: to include spin, we just tensor our previous Hilbert space with a...