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The role of differential equations in the process of calculating Feynman integrals is reviewed. An example of a diagram is given for which the method of differential equations was introduced, the properties of the inverse-mass-expansion…

High Energy Physics - Phenomenology · Physics 2021-07-23 A. V. Kotikov

In perturbative calculations, e.g., in the setting of Quantum Chromodynamics (QCD) one aims at the evaluation of Feynman integrals. Here one is often faced with the problem to simplify multiple nested integrals or sums to expressions in…

Symbolic Computation · Computer Science 2018-09-18 Johannes Blümlein , Carsten Schneider

FeynRules is a Mathematica-based package which addresses the implementation of particle physics models, which are given in the form of a list of fields, parameters and a Lagrangian, into high-energy physics tools. It calculates the…

High Energy Physics - Phenomenology · Physics 2014-05-30 Adam Alloul , Neil D. Christensen , Celine Degrande , Claude Duhr , Benjamin Fuks

We present a novel approach to optimizing the reduction of Feynman integrals using integration-by-parts identities. By developing a priority function through the FunSearch algorithm, which combines large language models and genetic…

High Energy Physics - Phenomenology · Physics 2025-02-14 Zhuo-Yang Song , Tong-Zhi Yang , Qing-Hong Cao , Ming-xing Luo , Hua Xing Zhu

The differential-reduction algorithm, which allows one to express generalized hypergeometric functions with parameters of arbitrary values in terms of such functions with parameters whose values differ from the original ones by integers, is…

High Energy Physics - Theory · Physics 2010-05-19 Vladimir V. Bytev , Mikhail Yu. Kalmykov , Bernd A. Kniehl

New developments concerning the extension of the recently introduced Feynman diagram analyser DIANA are presented.

High Energy Physics - Phenomenology · Physics 2009-10-31 J. Fleischer , M. Tentyukov

The reduction of Feynman integrals to a basis of linearly independent master integrals is a pivotal step in loop calculations, but also one of the main bottlenecks. In this paper, we assess the impact of using transverse integration…

High Energy Physics - Phenomenology · Physics 2025-06-17 Vsevolod Chestnov , Gaia Fontana , Tiziano Peraro

Integration-by-parts reductions of Feynman integrals pose a frequent bottle-neck in state-of-the-art calculations in theoretical particle and gravitational-wave physics, and rely on heuristic approaches for selecting integration-by-parts…

High Energy Physics - Theory · Physics 2025-02-10 Matt von Hippel , Matthias Wilhelm

FIRE7 is a major update to the FIRE program for integration-by-parts (IBP) reduction of Feynman integrals. A large part of improvements is related to the automatic reduction and reconstruction with the modular arithmetic approach, while the…

High Energy Physics - Phenomenology · Physics 2025-12-02 Alexander V. Smirnov , Mao Zeng

It was observed that hyperlogarithms provide a tool to carry out Feynman integrals. So far, this method has been applied successfully to finite single-scale processes. However, it can be employed in more general situations. We give examples…

High Energy Physics - Theory · Physics 2014-04-01 Erik Panzer

FIRE is a program which performs integration-by-parts (IBP) reduction of Feynman integrals. Originally, the C++ version of FIRE relies on the computer algebra system Fermat by Robert Lewis to simplify rational functions. We present an…

High Energy Physics - Phenomenology · Physics 2025-07-17 Alexander V. Smirnov , Mao Zeng

Since Feynman integrals (FIs) at higher spacetime dimensions are free of infrared and collinear divergence--and their ultraviolet divergences can be systematically subtracted--this allows us to construct a wide range of locally finite…

High Energy Physics - Phenomenology · Physics 2025-04-25 Yan-Qing Ma , Cong-Hao Qin , Ao Tan , Kai Yan

In this presentation, we review the general features of integrand-reduction techniques, with a particular focus on their generalization beyond one loop. We start with a brief discussion of the one-loop scenario, a case in which…

High Energy Physics - Phenomenology · Physics 2016-08-01 Giovanni Ossola

In this paper, we give a detailed account of the algorithm outlined in [1] for Feynman integral reduction and $\varepsilon$-factorised differential equations. The algorithm consists of two steps. In the first step, we use a new geometric…

The theory of graphical functions is generalized from scalar theories to theories with spin, leading to a numerator structure in Feynman integrals. The main part of this article treats the case of positive integer spin, which is obtained…

High Energy Physics - Theory · Physics 2025-05-12 Oliver Schnetz

We present a new package for Mathematica system, called Libra. Its purpose is to provide convenient tools for the transformation of the first-order differential systems $\partial_i \boldsymbol j = M_i \boldsymbol j$ for one or several…

High Energy Physics - Phenomenology · Physics 2021-07-07 Roman N. Lee

The method of differential equations has been proven to be a powerful tool for the computation of multi-loop Feynman integrals appearing in quantum field theory. It has been observed that in many instances a canonical basis can be chosen,…

High Energy Physics - Phenomenology · Physics 2017-05-23 Christoph Meyer

The 4-th order Runge-Kutta method in the complex plane is proposed for numerically advancing the solutions of a system of first order differential equations in one external invariant satisfied by the master integrals related to a Feynman…

High Energy Physics - Phenomenology · Physics 2007-05-23 Michele Caffo

We present a new interface called FeynHelpers that connects FeynCalc, a Mathematica package for symbolic semi-automatic evaluation of Feynman diagrams and calculations in quantum field theory (QFT) to Package-X and FIRE. The former provides…

Computational Physics · Physics 2018-01-30 Vladyslav Shtabovenko

We report on the calculation of multi-loop Feynman integrals for single-scale problems by means of difference equations in Mellin space. The solution to these difference equations in terms of harmonic sums can be constructed algorithmically…

Mathematical Physics · Physics 2008-12-18 S. Moch , C. Schneider