English
Related papers

Related papers: Determining Feynman integrals with only input from…

200 papers

In modern quantum field theory, one of the most important tasks is the calculation of loop integrals. Loop integrals appear when evaluating the Feynman diagrams with one or more loops by integrating over the internal momenta. Even though…

High Energy Physics - Theory · Physics 2020-06-24 Maxim Bezuglov

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

This course on Feynman integrals starts from the basics, requiring only knowledge from special relativity and undergraduate mathematics. Topics from quantum field theory and advanced mathematics are introduced as they are needed. The course…

High Energy Physics - Theory · Physics 2022-06-15 Stefan Weinzierl

The analytic integration and simplification of multi-loop Feynman integrals to special functions and constants plays an important role to perform higher order perturbative calculations in the Standard Model of elementary particles. In this…

High Energy Physics - Theory · Physics 2023-01-11 Johannes Blümlein , Carsten Schneider

A Feynman formula is a representation of a solution of an initial (or initial-boundary) value problem for an evolution equation (or, equivalently, a representation of the semigroup resolving the problem) by a limit of $n$-fold iterated…

Probability · Mathematics 2017-08-09 Yana A. Butko , René L. Schilling , Oleg G. Smolyanov

In recent years, differential equations have become the method of choice to compute multi-loop Feynman integrals. Whenever they can be cast into canonical form, their solution in terms of special functions is straightforward. Recently,…

High Energy Physics - Phenomenology · Physics 2023-08-28 Christoph Dlapa , Johannes M. Henn , Fabian J. Wagner

Numerical evaluations of Feynman integrals often proceed via a deformation of the integration contour into the complex plane. While valid contours are easy to construct, the numerical precision for a multi-loop integral can depend…

High Energy Physics - Phenomenology · Physics 2023-05-22 Ramon Winterhalder , Vitaly Magerya , Emilio Villa , Stephen P. Jones , Matthias Kerner , Anja Butter , Gudrun Heinrich , Tilman Plehn

By carefully analyzing the relations between operator methods and the discretized and continuum path integral formulations of quantum-mechanical systems, we have found the correct Feynman rules for one-dimensional path integrals in curved…

High Energy Physics - Theory · Physics 2009-10-28 Jan de Boer , Bas Peeters , Kostas Skenderis , Peter van Nieuwenhuizen

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 report on a new method for the numerical evaluation of loop integrals, based on the Feynman Tree Theorem. The loop integrals are replaced by phase-space integration over fictitious extra on-shell particles. This integration can be…

High Energy Physics - Phenomenology · Physics 2010-02-08 Wolfgang Kilian , Tobias Kleinschmidt

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

Deriving a comprehensive set of reduction rules for Feynman integrals has been a longstanding challenge. In this paper, we present a proposed solution to this problem utilizing generating functions of Feynman integrals. By establishing and…

High Energy Physics - Phenomenology · Physics 2023-06-29 Xin Guan , Xiang Li , Yan-Qing Ma

We show that direct Feynman-parametric loop integration is possible for a large class of planar multi-loop integrals. Much of this follows from the existence of manifestly dual-conformal Feynman-parametric representations of planar loop…

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

The first application of a quantum algorithm to Feynman loop integrals is reviewed. The connection between quantum computing and perturbative quantum field theory is feasible due to fact that the two on-shell states of a Feynman propagator…

Quantum Physics · Physics 2022-11-11 Selomit Ramírez-Uribe

We present a set of Feynman integrals appearing in calculations of different QED processes to the one-loop accuracy. We consider scalar, vector, and tensor integrals with two, three, four and five denominators. The cases of equal and…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. B. Arbuzov , A. V. Belitsky , E. A. Kuraev , B. G. Shaikhatdenov

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 compute all planar two-loop six-point Feynman integrals entering scattering observables in massless gauge theories such as QCD. A central result of this paper is the formulation of the differential-equations method under the algebraic…

High Energy Physics - Phenomenology · Physics 2024-12-31 Samuel Abreu , Pier Francesco Monni , Ben Page , Johann Usovitsch

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

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

These lecture notes provide a self-contained introduction to Euler integrals, which are frequently encountered in applications. In particle physics, they arise as Feynman integrals or string amplitudes. Our four selected topics demonstrate…

Mathematical Physics · Physics 2023-11-01 Saiei-Jaeyeong Matsubara-Heo , Sebastian Mizera , Simon Telen