Dirac's 1928 derivation of the hydrogen fine-structure splitting from the relativistic Dirac equation: energy levels depend on principal n and total angular momentum j through E_{n,j} = m c^2 [1 + (alpha / (n - j - 1/2 + sqrt((j+1/2)^2 -…
Dirac's 1928 derivation of the hydrogen fine-structure splitting from the relativistic Dirac equation: energy levels depend on principal n and total angular momentum j through E_{n,j} = m c^2 [1 + (alpha / (n - j - 1/2 + sqrt((j+1/2)^2 -…