Vector Spaces of Generalized Euler Integrals
Daniele Agostini, Claudia Fevola, Anna-Laura Sattelberger, Simon Telen
TL;DR
This work unifies several perspectives on vector spaces generated by generalized Euler integrals, showing that, for generic data, the dimension of the spaces obtained by varying integration parameters, Mellin-transform parameters, or GKZ-system parameters all coincide and equal $(-1)^n\chi(X)$ for the very affine variety $X=(\mathbb{C}^*)^n\setminus V(f_1\cdots f_\ell)$. It builds a coherent bridge between twisted de Rham theory, Mellin-transform methods, and $A$-hypergeometric (GKZ) systems, proving that the corresponding solution spaces are isomorphic and governed by the topology of $X$ (via Euler characteristics) or its Newton-polytope under suitable non-degeneracy assumptions. The paper derives explicit IBP-type relations from the twisted de Rham framework, connects these to Bernstein–Sato theory, and places the discussion in a computational context with both symbolic and numerical approaches, including fast GKZ-rank computations and numerical homotopy methods for counting critical points. Together these results yield a versatile toolkit for master integrals across physics and mathematics, with practical algorithms for computing relations and dimensions. The combination of D-module theory, GKZ systems, and numerical nonlinear algebra provides a robust path from integrals to linear relations and dimensional invariants, illuminating the role of topology in the structure of Feynman-type integrals and their generalizations.
Abstract
We study vector spaces associated to a family of generalized Euler integrals. Their dimension is given by the Euler characteristic of a very affine variety. Motivated by Feynman integrals from particle physics, this has been investigated using tools from homological algebra and the theory of $D$-modules. We present an overview and uncover new relations between these approaches. We also provide new algorithmic tools.
