Sign error in problem set etc

In the problem set given out recently, there was a typo in the third relation, namely a missing minus sign. The correct relation is:

{\bar\psi} \gamma^\mu \lambda = - {\bar\lambda} \gamma^\mu \psi

This is in fact the reason why {\bar\psi} \gamma^\mu \psi vanishes in the Majorana case, consistent with the fact that there should be no charge current in this case.

Also, there has been a request to include details about charge conjugation and Majorana matrices, and also another request to explicitly put in the various gamma-matrix representations in the notes. I will do these things next week.