Consider eigenenergies of bound states in a central potential.
(a) The radial quantum number n = 0, 1, 2, ... labels solutions of the radial equation with a given angular momentum l in order of increasing energies, i.e., E0,l < E1,l < E2,l < ...
Show that En,l with fixed n increases with l. Suggestion: apply the Hellmann-Feynman theorem [recall Problem 4] to the radial equation.
(b) Instead of n and l, the eigenenergies can be labeled by the principal quantum number n = 1, 2, 3... such that E1 < E2 < E3 < ...
What is the largest possible value of l for a given n?
What is the largest possible degeneracy of the bound state with eigenenergy En?