Name: Vladyslav Shtabovenko Date: 06/01/16-11:43:35 AM Z
Hi,
could you please provide a minimal sample code where this happens?
By default PaVeReduce should leave A0[m^2] or equivalently
PaVe[0, {},
{m^2}] untouched, which is what I’m currently observing:
$LoadAddOns = {“FeynHelpers”};
«FeynCalc`
A0[m^2] // PaVeReduce
PaVe[0, {}, {m^2}] // PaVeReduce
A0 of course can be converted to B0 via the option A0ToB0 of the
“direct” A0 function. Here I have
$LimitTo4 = True;
res1=A0[m^2, A0ToB0 -> True]
-> m^2 + m^2 B0[0, m^2, m^2]
$LimitTo4 = False;
res2=A0[m^2, A0ToB0 -> True]
-> -((2 m^2 B0[0, m^2, m^2])/(2 - D))
The same can be also achieved with PaVeReduce by using the same option:
$LimitTo4 = True;
A0[m^2] // PaVeReduce[#, A0ToB0 -> True] &
PaVe[0, {}, {m^2}] // PaVeReduce // PaVeReduce[#, A0ToB0
-> True] &
$LimitTo4 = False;
A0[m^2] // PaVeReduce[#, A0ToB0 -> True] &
PaVe[0, {}, {m^2}] // PaVeReduce // PaVeReduce[#, A0ToB0
-> True] &
Both res1 and res2 are correct, as can be seen by comparing
the explicit analytic results:
PaXEvaluate[res1] - PaXEvaluate[res2]
-> 0
The only way to obtain m^2*B0[0, m^2, m^2] that I currently see
would
be take the D->4 limit via
res2/.D->4
which is however not correct, since B0[0, m^2, m^2] is UV
divergent and
thus there is a finite contribution from multiplying the 1/Epsilon
pole
with the 1/(2-D) prefactor.
So a real example would be very helpful to understand what is the
problem that you are experiencing.
Cheers,
Vladyslav
Am 01.06.2016 um 11:24 schrieb Steffen Schwertfeger:
> Dear all,
>
> using the latest dev version of FeynCalc I can not reproduce some of
my
> earlier results. I also noticed that A0[m^2] reduces to
>
> m^2*B0[0, m^2, m^2]
>
> while the latest stable release yields
>
> m^2 + m^2*B0[0, m^2, m^2].
>
> Now I am not 100% certain that this is an error or a question of
> definition.
>
> Kind regards,
> Steffen Schwertfeger
>