Attempts at relativistic quantum mechanics — Mark Srednicki
Physics — QFT · dirac-matrices-even-dimensional
Problem
Show that the Dirac matrices must be even dimensional. Hint: show that the eigenvalues of β are all ±1, and that Trβ=0. To show that Trβ=0, consider, e.g., Trα12β. Similarly, show that Trαi=0.