2
votes
2answers
202 views

Finding wave-fuctions of a Dirac particle for given 4-momentum and spin 4-vector

I've been reading through various materials on relativistic quantum mechanics, but I find the lack of simple examples disturbing. I'm acquainted with the general form the solutions to the Dirac ...
5
votes
4answers
1k views

Why are four-vectors needed in the Dirac equation, when there are 4 linearly independent 2D matrices?

I was taught that for the Dirac-equation to "work", you need matrices of the following form: $Tr(\alpha^i) = 0$. Eigenvalues +1 or -1 2 previous points together: equal number of negative and ...