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A method for the evaluation of the epsilon expansion of multi-loop massless Feynman integrals is introduced. This method is based on the Gegenbauer polynomial technique and the expansion of the Gamma function in terms of harmonic sums.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Bekavac

The method of Symmetries of Feynman Integrals defines for any Feynman diagram a set of partial differential equations. On some locus in parameter space the equations imply that the diagram can be reduced to a linear combination of simpler…

High Energy Physics - Theory · Physics 2018-04-05 Barak Kol

We introduce an algebro-geometrically motived integration-by-parts (IBP) reduction method for multi-loop and multi-scale Feynman integrals, using a framework for massively parallel computations in computer algebra. This framework combines…

The algebraic approach to quantum mechanics has been vital to the development of quantum theory since its inception, and it has evolved into a mathematically rigorous $C^\ast$-algebraic formulation of the theory's axioms. Conversely, the…

Mathematical Physics · Physics 2022-03-31 John LaChapelle

In this talk we discuss a class of Feynman integrals, which can be expressed to all orders in the dimensional regularisation parameter as iterated integrals of modular forms. We review the mathematical prerequisites related to elliptic…

High Energy Physics - Phenomenology · Physics 2018-07-04 Luise Adams , Stefan Weinzierl

We review the method of the differential equations for the evaluation of multi-loop Feynman integrals. In particular, we focus on the series expansion approach for solving the system of differential equation and we discuss how to perform…

High Energy Physics - Phenomenology · Physics 2025-11-21 Tommaso Armadillo

A formalism for the numerical integration of one- and two-loop integrals is presented. It is based on subtraction terms which remove the soft, collinear and some of the ultraviolet divergences from the integrand. The numerical integral is…

High Energy Physics - Phenomenology · Physics 2012-10-08 A. Freitas

Single-scale Feynman diagrams yield integrals that are periods, namely projective integrals of rational functions of Schwinger parameters. Algebraic geometry may therefore inform us of the types of number to which these integrals evaluate.…

High Energy Physics - Theory · Physics 2014-09-22 David Broadhurst , Oliver Schnetz

The three-loop banana integral with three equal masses and the conformal two-loop five-point traintrack integral in two dimensions are related to a two-parameter family of K3 surfaces. We compute the corresponding periods and the mirror…

High Energy Physics - Theory · Physics 2025-02-24 Claude Duhr , Sara Maggio

Feynman integrals are central to all calculations in perturbative Quantum Field Theory. They often give rise to iterated integrals of dlog-forms with algebraic arguments, which in many cases can be evaluated in terms of multiple…

High Energy Physics - Theory · Physics 2020-06-18 Francis Brown , Claude Duhr

We present a novel technique for the analytic evaluation of multifold Mellin-Barnes (MB) integrals, which commonly appear in physics, as for instance in the calculations of multi-loop multi-scale Feynman integrals. Our approach is based on…

High Energy Physics - Theory · Physics 2023-09-04 Sumit Banik , Samuel Friot

This article gives a short step-by-step introduction to the representation of parametric Feynman integrals in scalar perturbative quantum field theory as periods of motives. The application of motivic Galois theory to the algebro-geometric…

Mathematical Physics · Physics 2021-03-30 Claudia Rella

In this paper, we investigate two-loop non-planar triangle Feynman integrals involving elliptic curves. In contrast to the Sunrise and Banana integral families, the triangle families involve non-trivial sub-sectors. We show that the…

High Energy Physics - Theory · Physics 2023-09-12 Xuhang Jiang , Xing Wang , Li Lin Yang , Jingbang Zhao

For Z -> b bbar, we calculate all the two-loop top dependent Feynman graphs, which have mixed QCD and electroweak contributions that are not factorizable. For evaluating the graphs, without resorting to a mass expansion, we apply a two-loop…

High Energy Physics - Phenomenology · Physics 2009-10-31 Adrian Ghinculov , York-Peng Yao

We show that momentum space Feynman diagrams involving internal massless fields can be cast as conformal integrals. This leads to a classification of all Feynman diagrams into conformal families, labelled by conformal integrals. Computing…

High Energy Physics - Theory · Physics 2025-01-03 Siddharth G. Prabhu

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

The predictions of the standard model of particle physics are highly successful in spite of the fact that several parts of the underlying quantum field theoretical framework are analytically problematic. Indeed, it has long been suggested,…

Mathematical Physics · Physics 2021-05-05 David M. Jackson , Achim Kempf , Alejandro H. Morales

New methods for obtaining functional equations for Feynman integrals are presented. Application of these methods for finding functional equations for various one- and two- loop integrals described in detail. It is shown that with the aid of…

High Energy Physics - Phenomenology · Physics 2015-12-31 O. V. Tarasov

Canonical Feynman integrals are of great interest in the study of scattering amplitudes at the multi-loop level. We propose to construct $d\log$-form integrals of the hypergeometric type, treat them as a representation of Feynman integrals,…

High Energy Physics - Theory · Physics 2021-02-03 Jiaqi Chen , Xuhang Jiang , Xiaofeng Xu , Li Lin Yang

This article reports an automated approach to the evaluation of higher-order terms of QED perturbation to anomalous magnetic moments of charged leptons by numerical means. We apply this approach to tenth-order correction due to a particular…

High Energy Physics - Phenomenology · Physics 2009-11-11 T. Aoyama , M. Hayakawa , T. Kinoshita , M. Nio