Periods of Feynman Diagrams and GKZ D-Modules
Emad Nasrollahpoursamami
TL;DR
The paper establishes a principled bridge between perturbative Feynman amplitudes and GKZ A-Hypergeometric D-modules by casting amplitudes as periods of relative motives within a toric-geometry framework. It shows that amplitudes satisfy holonomic regular differential systems derived from GKZ theory, and provides a constructive parametric form based on Symanzik polynomials that connects to matroid polytopes. A comprehensive regularization strategy is developed, identifying pole structures via semi-non-resonant faces and yielding an explicit ε-expansion in dimensional regularization through GKZ relations. The culmination proves that, under suitable regularity conditions, amplitudes are periods of relative motives, enabling explicit computation without resolution of singularities and offering a clear path to renormalization within this geometric-analytic paradigm.
Abstract
We study differential equations for Feynman amplitudes and we show that the corresponding D-module is isomorphic to a GKZ D-modules. We show that the sheaf of solutions to the D-module is isomorphic to a certain relative homology and the amplitudes are periods of a relative motive. Using these ideas, we develop a method of regularization which specializes to dimensional regularization and analytic regularization.
