Name: Cesar Lattes Date: 03/24/15-10:46:15 PM Z


Hi,

I found a very strange behaviour of the function PaVeReduce when one of the variables is much smaller than the others. It seems that I don’t get the same reduce if I apply PaVeReduce before or after sending a specific variable to zero.

For instance, if I try to compute:

f1 = PaVe[0, 0, {0, 0, m1^2}, {0, m2^2, m2^2}] // PaVeReduce

and

PaVe[0, 0, {m0^2, 0, m1^2}, {0, m2^2, m2^2}] // PaVeReduce
f2 = % /. m0 -> 0 ,

then I get a result which is not zero:

f1 - f2 // Simplify
>>>1/2 m2^2 (C0(m1^2,0,0,m2^2,0,m2^2)-C0(0,m1^2,0,m2^2,0,m2^2)) ,

Am I doing something wrong? What is the good way to take this kind of limit?

Thanks in advance.
C. L.

PS. I’m using FeynCalc 8.2.0 and Mathematica 8.0 (for Students).