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We invent an automated method for computing the divergent part of Feynman integrals in dimensional regularization. Our method exploits simplifications from four-dimensional integration-by-parts identities. Leveraging algorithms from the…

High Energy Physics - Theory · Physics 2023-09-19 Johannes Henn , Rourou Ma , Kai Yan , Yang Zhang

We present a Mathematica package which finds a basis of master integrals for the Feynman integral reduction. In this basis the dependence on the dimensional regularization in the denominators factorizes in kinematic independent polynomials.

High Energy Physics - Phenomenology · Physics 2020-04-03 Johann Usovitsch

We present a detailed description of the recent idea for a direct decomposition of Feynman integrals onto a basis of master integrals by projections, as well as a direct derivation of the differential equations satisfied by the master…

We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general $q^2$ are…

High Energy Physics - Phenomenology · Physics 2017-02-01 Johannes M. Henn , Alexander V. Smirnov , Vladimir A. Smirnov

We propose a novel method to compute multi-loop master integrals by constructing and numerically solving a system of ordinary differential equations, with almost trivial boundary conditions. Thus it can be systematically applied to problems…

High Energy Physics - Phenomenology · Physics 2018-02-28 Xiao Liu , Yan-Qing Ma , Chen-Yu Wang

Feynman integrals are solutions to linear partial differential equations with polynomial coefficients. Using a triangle integral with general exponents as a case in point, we compare $D$-module methods to dedicated methods developed for…

High Energy Physics - Theory · Physics 2025-05-27 Johannes Henn , Elizabeth Pratt , Anna-Laura Sattelberger , Simone Zoia

We argue that the Mellin-Barnes representations of Feynman diagrams can be used for obtaining linear systems of homogeneous differential equations for the original Feynman diagrams with arbitrary powers of propagators without recourse to…

High Energy Physics - Theory · Physics 2015-06-05 Mikhail Yu. Kalmykov , Bernd A. Kniehl

Over the last year significant progress was made in the understanding of the computation of Feynman integrals using differential equations. These lectures give a review of these developments, while not assuming any prior knowledge of the…

High Energy Physics - Phenomenology · Physics 2015-06-23 Johannes M. Henn

We revisit the idea of numerically integrating the differential form of Feynman integrals. With a novel approach for the treatment of branch cuts, we develop an integrator capable of evaluating a basis of master integrals in double and…

High Energy Physics - Phenomenology · Physics 2026-03-06 Pau Petit Rosàs

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…

We elaborate on the method of differential equations for evaluating Feynman integrals. We focus on systems of equations for master integrals having a linear dependence on the dimensional parameter. For these systems we identify the criteria…

High Energy Physics - Phenomenology · Physics 2015-06-18 Mario Argeri , Stefano Di Vita , Pierpaolo Mastrolia , Edoardo Mirabella , Johannes Schlenk , Ulrich Schubert , Lorenzo Tancredi

Finite difference schemes are here solved by means of a linear matrix equation. The theoretical study of the related algebraic system is exposed, and enables us to minimize the error due to a finite difference approximation.

Analysis of PDEs · Mathematics 2007-05-23 Claire David

The $\varepsilon$-form of a system of differential equations for Feynman integrals has led to tremendeous progress in our abilities to compute Feynman integrals, as long as they fall into the class of multiple polylogarithms. It is…

High Energy Physics - Phenomenology · Physics 2019-12-09 Stefan Weinzierl

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…

We present a systematic method to derive an ordinary differential equation for any Feynman integral, where the differentiation is with respect to an external variable. The resulting differential equation is of Fuchsian type. The method can…

High Energy Physics - Phenomenology · Physics 2015-06-12 Stefan Müller-Stach , Stefan Weinzierl , Raphael Zayadeh

A purely numerical method, Direct ComputationMethod is applied to evaluate Feynman integrals. This method is based on the combination of an efficient numerical integration and an efficient extrapolation. In addition, high-precision…

High Energy Physics - Phenomenology · Physics 2014-11-18 F. Yuasa , T. Ishikawa , J. Fujimoto , N. Hamaguchi , E. de Doncker , Y. Shimizu

In this talk, we review a loop-by-loop approach used to generate differential equations for multi-scale (dual) Feynman integrals. We illustrate the method on a well-established example: the unequal mass elliptic sunrise.

High Energy Physics - Theory · Physics 2023-09-12 Mathieu Giroux , Andrzej Pokraka , Franziska Porkert , Yoann Sohnle

In this paper we develop further and refine the method of differential equations for computing Feynman integrals. In particular, we show that an additional iterative structure emerges for finite loop integrals. As a concrete non-trivial…

High Energy Physics - Theory · Physics 2015-06-19 Simon Caron-Huot , Johannes M. Henn

In this paper, we introduce a new method for calculating fractional integrals and differentials. The method involves an equation that we have obtained from infinite applied integration by parts. The equation works for special class of…

General Mathematics · Mathematics 2023-09-08 Oleg Yaremko , Andrey Yachmenev

The techniques of integration by parts and differential reduction differ in the counting of master integrals. This is illustrated using as an example the two-loop sunset diagram with on-shell kinematics. A new algebraic relation between the…

Mathematical Physics · Physics 2011-08-09 Mikhail Yu. Kalmykov , Bernd A. Kniehl