partial fractions loop integrals by decomposing them into simpler integrals that contain only linearly independent propagators. It uses FCApart as a backend and works and is suitable also for multiloop integrals. ApartFF effectively replaces the older function Apart2 and ScalarProductCancel which are now considered legacy.
- ApartFF uses FCApart as the backend for partial fractioning. The latter implements an algorithm which is very much based on the work and code of F. Feng (arXiv:1204.2314) that seems to employ a variety Leinartas's algorithm (see arXiv:1206.4740 for its description). Unlike Feng's $Apart that works on general multivariate polynomials, FCApart is tailored to work only with FeynCalc's FeynAmpDenominator and Pair objects, i.e. it is less general. For the original $Apart see https://github.com/F-Feng/APart