Feynman slash notation
In the study of Dirac fields in quantum field theory, Richard Feynman invented the convenient Feynman slash notation (less commonly known as the Dirac slash notation). If A is a covariant vector (i.e., a 1-form),
Using the anticommutators of the gamma matrices, one can show that for any and ,
where is the identity matrix in four dimensions. In particular,
- is the Levi-Civita symbol.
using the Dirac basis for the 's,
as well as the definition of four momentum
We see explicitly that
Similar results hold in other bases, such as the Weyl basis.