RGE Running with Mathematica
When Calculating RGEs, SARAH writes them into a file which can be used for a numerical evaluation of the RGEs in Mathematica. This file is stored in the same directory and called RunRGEs.m and provides a function called RunRGEs. The syntax of this function is
RunRGEs[values, start, finish, Options]The input is:
-
values: all non-zero values for parameters at the scale where the running starts -
start: logarithm of the scale where the running starts -
finish: logarithm of the scale where the running should end -
Options: optionally two-loop contributions can be turned off (TwoLoop->False)
Example
One can load the file for the MSSM and perform an one-loop running of the gauge couplings from 1 TeV to 1016 GeV via
<< "[\$SARAH-Directory]/Output/MSSM/RGEs/RunRGEs.m";
solution = RunRGEs[{g1->0.45, g2->0.63, g3->1.04},3,16, TwoLoop->False];Here, we saved the output of RunRGEs as variable, which can be used as follows
Plot[{g1[x],g2[x],g3[x]}/. solution[[1]], {x,3,16}];