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[1]). If A is a covariant vector (i.e., a 1-form),

where γ are the gamma matrices. Using the Einstein summation notation, the expression is simply

.
  1. ^ Weinberg, Steven (1995), The Quantum Theory of Fields, vol. 1, Cambridge University Press, p. 358 (380 in polish edition), ISBN 0-521-55001-7