Dirac matrices
= Dirac matrices
{c}
{title2=$\alpha_i,\beta$}
Matrices that factor the relativistic energy-momentum relation. In <Hamiltonian> form, $\alpha_i^2=\beta^2=I$, $\{\alpha_i,\alpha_j\}=2\delta_{ij}I$ and $\{\alpha_i,\beta\}=0$. A physical <Hamiltonian> uses <Hermitian matrices>; in three spatial dimensions the smallest complex representation has dimension four.