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Evaluation of three- and four-point diagrams with massless internal particles and arbitrary external momenta is considered. Exact results for some two-loop diagrams (planar and non-planar three-point contributions and the "double box"…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. I. Ussyukina , A. I. Davydychev

We show that for a class of two-loop diagrams, the on-shell part of the integration-by-parts (IBP) relations correspond to exact meromorphic one-forms on algebraic curves. Since it is easy to find such exact meromorphic one-forms from…

High Energy Physics - Theory · Physics 2016-01-27 Alessandro Georgoudis , Yang Zhang

Feynman integral reduction by means of integration-by-parts identities is a major power gadget in a theorist toolbox indispensable for calculation of multiloop quantum effects relevant for particle phenomenology and formal theory alike. An…

High Energy Physics - Phenomenology · Physics 2024-02-13 A. V. Belitsky , A. A. Kokosinskaya , A. V. Smirnov , V. V. Voevodin , M. Zeng

We present an analytic calculation of three-loop four-point Feynman integrals with two off-shell legs of equal mass. We provide solutions to the canonical differential equations of two integral families in both Euclidean and physical…

High Energy Physics - Phenomenology · Physics 2024-12-24 Ming-Ming Long

It is shown how strictly four-dimensional integration by parts combined with differential renormalization and its infrared analogue can be applied for calculation of Feynman diagrams.

High Energy Physics - Theory · Physics 2009-10-30 V. A. Smirnov

We show that the direct image of the filtered logarithmic de Rham complex is a direct sum of filtered logarithmic complexes with coefficients in variations of Hodge structures, using a generalization of the decomposition theorem of…

Algebraic Geometry · Mathematics 2007-05-23 Morihiko Saito

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 present an efficient algorithm for calculating multiloop Feynman integrals perturbatively.

Quantum Physics · Physics 2009-10-31 Boris Kastening , Hagen Kleinert

Integral-equation-based fast direct solvers for electromagnetic scattering can substantially reduce computational costs, especially in the presence of multiple excitations. We recently proposed a new high-frequency fast direct solver…

Numerical Analysis · Mathematics 2026-03-05 V. Giunzioni , C. Henry , A. Merlini , F. P. Andriulli

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

One problem which plagues the numerical evaluation of one-loop Feynman diagrams using recursive integration by part relations is a numerical instability near exceptional momentum configurations. In this contribution we will discuss a…

High Energy Physics - Phenomenology · Physics 2009-11-10 W. Giele , E. W. N. Glover , G. Zanderighi

It has recently been demonstrated that Feynman integrals relevant to a wide range of perturbative quantum field theories involve periods of Calabi-Yaus of arbitrarily large dimension. While the number of Calabi-Yau manifolds of dimension…

High Energy Physics - Theory · Physics 2022-08-24 Jacob L. Bourjaily , Andrew J. McLeod , Cristian Vergu , Matthias Volk , Matt von Hippel , Matthias Wilhelm

A connection between one-loop $N$-point Feynman diagrams and certain geometrical quantities in non-Euclidean geometry is discussed. A geometrical way to calculate the corresponding Feynman integrals is considered. (This paper contains a…

High Energy Physics - Theory · Physics 2011-03-17 A. I. Davydychev , R. Delbourgo

It is known that one-loop Feynman integrals possess an algebraic structure encoding some of their analytic properties called the coaction, which can be written in terms of Feynman integrals and their cuts. This diagrammatic coaction, and…

High Energy Physics - Theory · Physics 2019-12-16 Samuel Abreu , Ruth Britto , Claude Duhr , Einan Gardi , James Matthew

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

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

Multi-level numerical methods that obtain the exact solution of a linear system are presented. The methods are devised by combining ideas from the full multi-grid algorithm and perfect reconstruction filters. The problem is stated as…

Numerical Analysis · Mathematics 2015-05-14 Pablo Navarrete Michelini

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 logarithmic number system (LNS) is arguably not broadly used due to exponential circuit overheads for summation tables relative to arithmetic precision. Methods to reduce this overhead have been proposed, yet still yield designs with…

Numerical Analysis · Mathematics 2020-05-15 Jeff Johnson

In this talk we present techniques for calculating one-loop amplitudes for multi-leg processes using Feynman diagrammatic methods in a semi-algebraic context. Our approach combines the advantages of the different methods allowing for a fast…

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