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Related papers: Solving Recurrence Relations for Multi-Loop Feynma…

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We describe three algorithms for computer-aided symbolic multi-loop calculations that facilitated some recent novel results. First, we discuss an algorithm to derive the canonical form of an arbitrary Feynman integral in order to facilitate…

High Energy Physics - Phenomenology · Physics 2015-06-03 Alexey Pak

We reduce all the most complicated Feynman integrals in two-loop five-light-parton scattering amplitudes to basic master integrals, while other integrals can be reduced even easier. Our results are expressed as systems of linear relations…

High Energy Physics - Phenomenology · Physics 2020-09-11 Xin Guan , Xiao Liu , Yan-Qing Ma

The method for obtaining functional equations, recently proposed by one of the authors, is applied to one-loop box integrals needed in calculations of radiative corrections to heavy-quark production and Bhabha scattering. We present…

High Energy Physics - Phenomenology · Physics 2009-07-22 Bernd A. Kniehl , Oleg V. Tarasov

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 describe a method to numerically compute multi-loop integrals, depending on one dimensionless parameter $x$ and the dimension $d$, in the whole kinematic range of $x$. The method is based on differential equations, which, however, do not…

High Energy Physics - Phenomenology · Physics 2021-10-13 Matteo Fael , Fabian Lange , Kay Schönwald , Matthias Steinhauser

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

We initiate a systematic study of one-loop integrals by investigating the connection between their singularity structures and geometric configurations in the projective space associated to their Feynman parametrization. We analyze these…

High Energy Physics - Theory · Physics 2017-12-29 Nima Arkani-Hamed , Ellis Ye Yuan

An algorithm for the reduction of massive Feynman integrals with any number of loops and external momenta to a minimal set of basic integrals is proposed. The method is based on the new algorithm for evaluating tensor integrals,…

High Energy Physics - Phenomenology · Physics 2011-03-17 O. V. Tarasov

We define linearly reducible elliptic Feynman integrals, and we show that they can be algorithmically solved up to arbitrary order of the dimensional regulator in terms of a 1-dimensional integral over a polylogarithmic integrand, which we…

High Energy Physics - Phenomenology · Physics 2019-01-17 Martijn Hidding , Francesco Moriello

The standard procedure when evaluating integrals of a given family of Feynman integrals, corresponding to some Feynman graph, is to construct an algorithm which provides the possibility to write any particular integral as a linear…

High Energy Physics - Phenomenology · Physics 2021-02-23 A. V. Smirnov , V. A. Smirnov

We consider finite iterated generalized harmonic sums weighted by the binomial $\binom{2k}{k}$ in numerators and denominators. A large class of these functions emerges in the calculation of massive Feynman diagrams with local operator…

High Energy Physics - Theory · Physics 2015-06-22 J. Ablinger , J. Blümlein , C. G. Raab , C. Schneider

In this talk I review the connections between Feynman integrals and multiple polylogarithms. After an introductory section on loop integrals I discuss the Mellin-Barnes transformation and shuffle algebras. In a subsequent section multiple…

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

In this work, we systematically analyse Feynman integrals in the `t Hooft-Veltman scheme. We write an explicit reduction resulting from partial fractioning the high-multiplicity integrands to a finite basis of topologies at any given loop…

High Energy Physics - Phenomenology · Physics 2024-11-28 Piotr Bargiela , Tong-Zhi Yang

We proposed a recipe to systematically calculate Feynman integrals containing linear propagators using the auxiliary mass flow method. The key of the recipe is to introduce a quadratic term for each linear propagator and then using…

High Energy Physics - Phenomenology · Physics 2023-01-30 Zhi-Feng Liu , Yan-Qing Ma

Starting from the Mellin-Barnes integral representation of a Feynman integral depending on set of kinematic variables $z_i$, we derive a system of partial differential equations w.r.t.\ new variables $x_j$, which parameterize the…

High Energy Physics - Theory · Physics 2023-01-25 Vladimir V. Bytev , Bernd A. Kniehl , Oleg L. Veretin

We give a brief introduction to a parametric approach for the derivation of shift relations between Feynman integrals and a result on the number of master integrals. The shift relations are obtained from parametric annihilators of the…

High Energy Physics - Theory · Physics 2018-09-11 Thomas Bitoun , Christian Bogner , René Pascal Klausen , Erik Panzer

We show that the new relation between master integrals recently obtained in Ref. [1] can be reproduced using the integration-by-parts technique implemented with an effective mass. In fact, this relation is recovered as a special case of a…

High Energy Physics - Phenomenology · Physics 2015-06-04 Bernd A. Kniehl , Anatoly V. Kotikov

We present algorithms to work with iterated Eisenstein integrals that have recently appeared in the computation of multi-loop Feynman integrals. These algorithms allow one to analytically continue these integrals to all regions of the…

High Energy Physics - Theory · Physics 2020-03-18 Claude Duhr , Lorenzo Tancredi

The one-sided bouncer and the symmetric bouncer involve a one-dimensional particle in a piecewise linear potential. For such problems, the time-dependent quantum mechanical propagator cannot be found in closed form. The semiclassical…

Quantum Physics · Physics 2021-09-29 Yen Lee Loh , Chee Kwan Gan

We embed Feynman integrals in the subvarieties of Grassmannians through homogenization of the integrands in projective space, then obtain GKZ-systems satisfied by those scalar integrals. The Feynman integral can be written as linear…

High Energy Physics - Theory · Physics 2023-01-03 Tai-Fu Feng , Hai-Bin Zhang , Chao-Hsi Chang