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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

Recently in arXiv:2012.05599 Rudenko presented a formula for the volume of hyperbolic orthoschemes in terms of alternating polylogarithms. We use this result to provide an explicit analytic result for the one-loop scalar n-gon Feynman…

High Energy Physics - Theory · Physics 2024-04-15 Lecheng Ren , Marcus Spradlin , Cristian Vergu , Anastasia Volovich

We evaluate a four-loop conformal integral, i.e. an integral over four four-dimensional coordinates, by turning to its dimensionally regularized version and applying differential equations for the set of the corresponding 213 master…

High Energy Physics - Theory · Physics 2016-11-23 Burkhard Eden , Vladimir A. Smirnov

We review the Laporta algorithm for the reduction of scalar integrals to the master integrals and the differential equations technique for their evaluation. We discuss the use of the basis of harmonic polylogarithms for the analytical…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Bonciani

We introduce and study the Wilson-loop ${\rm d}\log$ representation of certain Feynman integrals for scattering amplitudes in ${\cal N}=4$ SYM and beyond, which makes their evaluation completely straightforward. Such a representation was…

High Energy Physics - Theory · Physics 2021-05-26 Song He , Zhenjie Li , Yichao Tang , Qinglin Yang

We present an algorithm for determining the minimal order differential equations associated to a given Feynman integral in dimensional or analytic regularisation. The algorithm is an extension of the Griffiths-Dwork pole reduction adapted…

High Energy Physics - Theory · Physics 2024-06-21 Leonardo de la Cruz , Pierre Vanhove

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

We develop a generating-function formulation for the symbolic reduction of multi-loop Feynman integrals. In this framework, integration-by-parts identities are rewritten as differential equations for sector-wise generating functions, so the…

High Energy Physics - Phenomenology · Physics 2026-05-12 Bo Feng , Xiang Li , Yuanche Liu , Yanqing Ma , Yang Zhang

The computation of Feynman integrals is often the bottleneck of multi-loop calculations. We propose and implement a new method to efficiently evaluate such integrals in the physical region through the numerical integration of a suitable set…

High Energy Physics - Phenomenology · Physics 2019-05-01 Manoj K. Mandal , Xiaoran Zhao

We present a simple method which simplifies the evaluation of the on-shell multiple box diagrams reducing them to triangle type ones. For the $L$-loop diagram one gets the expression in terms of Feynman parameters with $2L$-fold…

High Energy Physics - Theory · Physics 2015-06-18 D. I. Kazakov

A framework to represent and compute two-loop $N$-point Feynman diagrams as double-integrals is discussed. The integrands are 'generalised one-loop type" multi-point functions multiplied by simple weighting factors. The final integrations…

High Energy Physics - Phenomenology · Physics 2020-04-15 J. Ph. Guillet , E. Pilon , Y. Shimizu , M. S. Zidi

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

A scheme for systematically achieving accurate numerical evaluation of multi-loop Feynman diagrams is developed. This shows the feasibility of a project aimed to produce a complete calculation for two-loop predictions in the Standard Model.…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Passarino

A method for reducing Feynman integrals, depending on several kinematic variables and masses, to a combination of integrals with fewer variables is proposed. The method is based on iterative application of functional equations proposed by…

High Energy Physics - Phenomenology · Physics 2019-01-29 Tarasov O.

We present analytical results for one-loop five-point master integrals with up to three off-shell legs. The method of canonical differential equations along with the Simplified Differential Equations approach is employed. All necessary…

High Energy Physics - Phenomenology · Physics 2021-10-18 Dhimiter D. Canko , Costas G. Papadopoulos , Nikolaos Syrrakos

We apply a recently suggested new strategy to solve differential equations for Feynman integrals. We develop this method further by analyzing asymptotic expansions of the integrals. We argue that this allows the systematic application of…

High Energy Physics - Theory · Physics 2015-06-18 Johannes M. Henn , Alexander V. Smirnov , Vladimir A. Smirnov

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 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

New algebraic approach to analytical calculations of D-dimensional integrals for multi-loop Feynman diagrams is proposed. We show that the known analytical methods of evaluation of multi-loop Feynman integrals, such as integration by parts…

High Energy Physics - Theory · Physics 2010-04-05 A. P. Isaev

We study several multiscale one-loop five-point families of Feynman integrals. More specifically, we employ the Simplified Differential Equations approach to obtain results in terms of Goncharov polylogarithms of up to transcendental weight…

High Energy Physics - Phenomenology · Physics 2021-09-14 Nikolaos Syrrakos