Apr 23 Bedile pointed out that Shankar has a discussion of the L.S problem. You're welcome to use that for your homework (but reference it, as usual). Lecture notes should be up to date now (plus a little). For the second problem in the current set, to exponentiate S_2 to get the rotation matrix, simply write the taylor series using an arbitrary angle and the matrix for S_2. You should find that after you've worked out a few terms it will be obvious how the rest of them go. You'll end up with a 2x2 matrix of cosines and sines. At the end, consider the special case when the angle is pi/2, and apply it to the vector representing |1/2, 1/2>. Mar 23 I've added an identity to the statement of the third problem (about the Coulomb potential in the hydrogen atom) that will help with the angular integrals. Mar 17 Please note the minor correction in the last problem. (It's more subtle, because the states are degenerate.) Mar 11 For the question about the leading asymptotic behavior of solutions to the 1d Schrodinger equation, what I have in mind is what we did to get the exponential behavior of the radial hydrogen wavefunction. Recall that we extracted this before attempting a series solution by assuming a form exp(S), and looking for the largest contribution to S for large r. Feb 16 I've updated lectures to cover material just a bit beyond where we are in class. Jan 13 The time on Tu-Thurs pm originally scheduled conflicted with another class. I'll contact you soon to set up a new schedule, but please feel free to communicate preferences before then. My inclination is some time on Tu-Thurs afternoon, though we could also try a MW or WF am.