Name: huiyoung Date: 03/16/07-03:27:27 PM Z


Hello

Nowadays I have calculted some quantity including Dirac Matrix.

My question is as follows:
In ‘Feyncalc’, we don’t need to write IdentityMatrix[4]?
For example, I want to express
GS[p]+a ,
where GS[p] is 4-dim matrix, but a is scalar. Actually
a is not a scalar but a*IdentityMatrix[4]. So my question
is : what is right ?
 1. GS[p]+a
 2. GS[p]+a IdentityMatrix[4]

Thanks.