FCLoopGetEtaSigns[exp]
is an auxiliary function that extracts the signs of from propagators present in the input expression. The result is returned as a list, e.g. {}
, {1}
, {-1}
or {-1,1}
.
This is useful if one wants ensure that all propagators of the given integral or topology follow a particular sign convention.
Overview, FCTopology, FCLoopSwitchEtaSign.
[{p, m}]
FAD
[%] FCLoopGetEtaSigns
[{p, m^2}]
SFAD
[%] FCLoopGetEtaSigns
[{I p, -m^2}, EtaSign -> -1]
SFAD
[%] FCLoopGetEtaSigns
[{p, m^2}]
CFAD
[%] FCLoopGetEtaSigns