Improving integration-by-parts and differential equations
Iris Bree, Federico Gasparotto, Antonela Matijašić, Pouria Mazloumi, Dmytro Melnichenko, Sebastian Pögel, Toni Teschke, Xing Wang, Stefan Weinzierl, Konglong Wu, Xiaofeng Xu
TL;DR
The talk addresses the computational bottlenecks in Feynman integral reduction and in constructing $\varepsilon$-factorised differential equations. It introduces a geometry-driven Laporta ordering based on the maximal-cut Baikov representation and twisted cohomology, complemented by three filtrations, to guide master-integral selection and to decompose the integral space. A new extended order relation significantly reduces reduction sizes and can be combined with finite-field and other optimisations; separately, the basis obtained from this ordering yields differential equations on the maximal cut that are $\varepsilon$-factorised via a transforming matrix $R_2$, with a procedure to handle sub-sectors and rational $\varepsilon$-dependence. Importantly, the framework works without requiring explicit prior knowledge of the underlying geometry (e.g., elliptic or higher-genus structures) and relies on concepts from twisted cohomology and Hodge theory to achieve robust, algorithmic construction of $\varepsilon$-factorised differential equations. These advances promise improvements in both analytic and numerical perturbative quantum-field-theory calculations.
Abstract
In this talk, we discuss how ideas from geometry help to improve Feynman integral reduction and the construction of $\varepsilon$-factorised differential equations. In particular, we outline a systematic procedure to obtain an $\varepsilon$-factorised differential equation for any Feynman integral.
