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FeynCalc / feyncalc

Mathematica package for algebraic calculations in elementary particle physics.
https://feyncalc.github.io
GNU General Public License v3.0
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Add Schwinger, Lee-Pomeransky and Baikov parametrization to FCFeymanParametrize. #89

Open vsht opened 3 years ago

vsht commented 3 years ago

FCFeynmanParametrize currently supports only Feynman parametrization. It would be good to have Schwinger, Lee-Pomeransky and Baikov working as well. At least for pure denominator integrals.

vsht commented 2 years ago

Lee-Pomeransky is already available (purely scalar case only), cf.

FCFeynmanParametrize[{SFAD[{ p1, m^2}], SFAD[{ p3, m^2}], 
   SFAD[{(p3 - p1), m^2}], SFAD[{{0, 2 p1 . n}}], SFAD[{{0, 2 p3 . n}}]}, {p1, p3}, 
  Names -> x, Method -> "Lee-Pomeransky", FCReplaceD -> {D -> 4 - 2 ep}, 
  FinalSubstitutions -> {SPD[n] -> 1, m -> 1}]

Baikov would require a bit more work though ...