Integral reduction in parameter space using CALICO

by Gaia Fontana (University of Zürich)

Monday Apr 20, 2026, 2:00 PM → 3:00 PM Europe/Zurich

4/2-037 - TH meeting room (CERN)

The reduction of loop integrals to a basis of linearly independent master integrals is a crucial step for modern multiloop theoretical predictions. Traditionally, it is done in momentum space following the Laporta algorithm. In this talk we elaborate on the method of parametric annihilators for deriving relations among integrals. Annihilators are differential operators that annihilate multi-valued integration kernels. We describe a method for computing parametric annihilators and show how to use them to derive relations between a wide class of special functions. These include loop integrals relevant to high-energy physics in several parametric representations. We finally present the public Mathematica package CALICO for computing parametric annihilators and its usage in several examples. We also discuss modern applications of this technique and its combination with expansion by regions.

CERN_GF.pdf