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We introduce a machine-learning framework based on symbolic regression to extract the full symbol alphabet of multi-loop Feynman integrals. By targeting the analytic structure rather than reduction, the method is broadly applicable and…

High Energy Physics - Phenomenology · Physics 2025-10-28 Yuanche Liu , Yingxuan Xu , Yang Zhang

We propose an algorithm for the application of the Laplace method for the calculation of the simplest Feynman diagram with a single loop in the scalar {\phi}^3 theory. The calculation of the contribution of such a diagram to the scattering…

High Energy Physics - Phenomenology · Physics 2022-05-31 I. V. Sharph , T. M. Zelentsova , N. O. Chudak , O. S. Potiienko , D. A. Ptashynskiy , K. K. Merkotan , T. V. Yushkevich , A. O. Milieva

In these lectures I discuss Feynman graphs and the associated Feynman integrals. Of particular interest are the classes functions, which appear in the evaluation of Feynman integrals. The most prominent class of functions is given by…

High Energy Physics - Phenomenology · Physics 2013-01-30 Stefan Weinzierl

One of the most severe bottlenecks to reach high-precision predictions in QFT is the calculation of multiloop multileg Feynman integrals. Several new strategies have been proposed in the last years, allowing impressive results with deep…

High Energy Physics - Theory · Physics 2023-09-27 German F. R. Sborlini

The evaluation of quantum corrections in the theory of the electroweak and strong interactions via higher-order Feynman diagrams requires complicated and laborious calculations, which however can be structured in a strictly algorithmic way.…

High Energy Physics - Phenomenology · Physics 2009-11-07 G. Weiglein

In this paper it is shown how the generating functional for Green's functions in relativistic quantum field theory and in thermal field theory can be evaluated in terms of a standard quantum mechanical path integral. With this calculational…

High Energy Physics - Theory · Physics 2011-07-19 D. G. C. McKeon , A. Rebhan

In a recent paper \cite{ft} a new powerful method to calculate Feynman diagrams was proposed. It consists in setting up a Taylor series expansion in the external momenta squared. The Taylor coefficients are obtained from the original…

High Energy Physics - Phenomenology · Physics 2016-09-01 J. Fleischer , O. V. Tarasov

The standard procedure for computing scalar multi-loop Feynman integrals consists in reducing them to a basis of so-called master integrals, derive differential equations in the external invariants satisfied by the latter and, finally, try…

High Energy Physics - Phenomenology · Physics 2017-04-05 Amedeo Primo , Lorenzo Tancredi

We discuss a progress in calculation of Feynman integrals which has been done with help of the Differential Equation Method and demonstrate the results for a class of two-point two-loop diagrams.

High Energy Physics - Phenomenology · Physics 2007-05-23 A. V. Kotikov

The two-loop QCD corrections to vector boson pair production at hadron colliders involve a new class of Feynman integrals: two-loop four-point functions with two off-shell external legs. We describe their reduction to a small set of master…

High Energy Physics - Phenomenology · Physics 2013-08-26 Thomas Gehrmann , Lorenzo Tancredi , Erich Weihs

We provide a comprehensive summary of concepts from Calabi-Yau motives relevant to the computation of multi-loop Feynman integrals. From this we derive several consequences for multi-loop integrals in general, and we illustrate them on the…

High Energy Physics - Theory · Physics 2022-10-19 Kilian Bönisch , Claude Duhr , Fabian Fischbach , Albrecht Klemm , Christoph Nega

We compute the full set of two-loop Feynman integrals appearing in massless two-loop four-point functions with two off-shell legs with the same invariant mass. These integrals allow to determine the two-loop corrections to the amplitudes…

High Energy Physics - Phenomenology · Physics 2014-06-13 Thomas Gehrmann , Andreas von Manteuffel , Lorenzo Tancredi , Erich Weihs

We propose a variant of elliptic multiple polylogarithms that have at most logarithmic singularities in all variables and satisfy a differential equation without homogeneous term. We investigate several non-trivial elliptic two-loop Feynman…

High Energy Physics - Theory · Physics 2019-01-30 Johannes Broedel , Claude Duhr , Falko Dulat , Brenda Penante , Lorenzo Tancredi

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

Multi-loop scattering amplitudes constitute a serious bottleneck in current high-energy physics computations. Obtaining new integrand level representations with smooth behaviour is crucial for solving this issue, and surpassing the…

High Energy Physics - Phenomenology · Physics 2021-09-17 German F. R. Sborlini

This is a status report of the evaluation of the three-loop corrections to the static QCD potential of a heavy quark and an antiquark. The families of Feynman integrals that appear in the evaluation are described. To reduce any integral of…

High Energy Physics - Phenomenology · Physics 2015-05-13 Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

New analytic formulas for one-loop three-point Feynman integrals in general space-time dimension ($d$) are presented in this paper. The calculations are performed at general configurations for internal masses and external momenta. The…

High Energy Physics - Phenomenology · Physics 2019-12-06 Khiem Hong Phan , Dzung Tri Tran

By introducing an auxiliary parameter, we find a new representation for Feynman integrals, which defines a Feynman integral by analytical continuation of a series containing only vacuum integrals. The new representation therefore…

High Energy Physics - Phenomenology · Physics 2019-04-17 Xiao Liu , Yan-Qing Ma

We present an algorithm to evaluate multiloop Feynman integrals with an arbitrary number of internal massive lines, with the masses being in general complex-valued, and its implementation in the \textsc{Mathematica} package…

High Energy Physics - Phenomenology · Physics 2022-10-24 Tommaso Armadillo , Roberto Bonciani , Simone Devoto , Narayan Rana , Alessandro Vicini

This paper describes a method of numerical evaluating high-order QED contributions to the electron anomalous magnetic moment. The method is based on subtraction of infrared and ultraviolet divergences in Feynman-parametric space before…

High Energy Physics - Phenomenology · Physics 2018-11-07 Sergey Volkov