The Dirac matrices are to 3+1D what "those matrices" are to 4D - What are "those matrices"?

38 Views Asked by At

The Dirac matrix have the following properties

$$ \gamma_\mu\gamma_\nu = \eta_{\mu\nu}\\ $$

This works in 3+1D because the signature is $(+,-,-,-)$.

They can be used to represent a vector in 3+1D like this $v = t\gamma_0+ x\gamma_1+y\gamma_2+z\gamma_3$.


In 3D, we have the Pauli matrices

$$ \sigma_i\sigma_j = \delta_{ij} $$

One can write a vector in 3D like this $v=x\gamma_x+y\gamma_y+z\gamma_z$.


I am looking for 4x4 matrices which works for signature $(+,+,+,+)$. The properties would be

$$ \mathbf{\hat{x}}_i \mathbf{\hat{x}}_j= \delta_{ij} $$

The matrices would be 4x4 and would allow one to write a vector $v=x \mathbf{\hat{x}} + y \mathbf{\hat{y}} + z \mathbf{\hat{z}} + w\mathbf{\hat{w}}$

Are these matrices known? I would like to know the entries of those matrices.