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In this work we calculate two two-loop massless Feynman integrals pertaining to self-energy diagrams using NDIM (Negative Dimensional Integration Method). We show that the answer we get is 36-fold degenerate. We then consider special cases…

High Energy Physics - Theory · Physics 2011-09-13 Alfredo T. Suzuki , Alexandre G. M. Schmidt

We study massive one-loop integrals by analytically continuing the Feynman integral to negative dimensions as advocated by Halliday and Ricotta and developed by Suzuki and Schmidt. We consider n-point one-loop integrals with arbitrary…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. Anastasiou , E. W. N. Glover , C. Oleari

Feynman diagrams are the best tool we have to study perturbative quantum field theory. For this very reason the development of any new technique which allows us to compute Feynman integrals is welcome. By the middle of the 80's, Halliday…

High Energy Physics - Theory · Physics 2007-05-23 Alfredo T. Suzuki , Alexandre G. M. Schmidt

Using the Feynman parameter method, we have calculated in an elegant manner a set of one$-$loop box scalar integrals with massless internal lines, but containing 0, 1, 2, or 3 external massive lines. To treat IR divergences (both soft and…

High Energy Physics - Phenomenology · Physics 2009-01-07 G. Duplancic , B. Nizic

A formalism for the numerical integration of one- and two-loop integrals is presented. It is based on subtraction terms which remove the soft, collinear and some of the ultraviolet divergences from the integrand. The numerical integral is…

High Energy Physics - Phenomenology · Physics 2012-10-08 A. Freitas

Two-loop vertex Feynman diagrams with infrared and collinear divergences are investigated by two independent methods. On the one hand, a method of calculating Feynman diagrams from their small momentum expansion extended to diagrams with…

High Energy Physics - Phenomenology · Physics 2011-09-13 J. Fleischer , V. A. Smirnov , A. Frink , J. KÖrner , D. Kreimer , K. Schilcher , J. B. Tausk

We present a systematic method for reducing an arbitrary one-loop N-point massless Feynman integral with generic 4-dimensional momenta to a set comprised of eight fundamental scalar integrals: six box integrals in D=6, a triangle integral…

High Energy Physics - Phenomenology · Physics 2009-11-10 G. Duplancic , B. Nizic

Perturbative quantum gauge field theory seen within the perspective of physical gauge choices such as the light-cone entails the emergence of troublesome poles of the type $(k\cdot n)^{-\alpha}$ in the Feynman integrals, and these come from…

High Energy Physics - Theory · Physics 2011-09-13 Alfredo T. Suzuki , Alexandre G. M. Schmidt

In this sequel calculation of the one-loop Feynman integral pertaining to a massive box diagram contributing to the photon-photon scattering amplitude in quantum electrodynamics, we present the six solutions as yet unknown in the…

High Energy Physics - Theory · Physics 2007-05-23 Alfredo T. Suzuki , Alexandre G. M. Schmidt

A comprehensive study is performed of two-loop Feynman diagrams with three external legs which, due to the exchange of massless gauge-bosons, give raise to infrared and collinear divergencies. Their relevance in assembling realistic…

High Energy Physics - Phenomenology · Physics 2009-11-11 Giampiero Passarino , Sandro Uccirati

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 introduce Linearly Constrained Diffusion Implicit Models (CDIM), a fast and accurate approach to solving noisy linear inverse problems using diffusion models. Traditional diffusion-based inverse methods rely on numerous projection steps…

Machine Learning · Computer Science 2025-12-01 Vivek Jayaram , Ira Kemelmacher-Shlizerman , Steven M. Seitz , John Thickstun

The differential equation method is applied to evaluate analytically two-loop vertex Feynman diagrams. Three on-shell infrared divergent planar two-loop diagrams with zero thresholds contributing to the processes Z --> bb bar (for zero b…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. Fleischer , A. V. Kotikov , O. L. Veretin

In this paper, we propose a new method for evaluating scalar one-loop Feynman integrals in generalized D-dimension. The calculations play an important building block for two-loop and higher-loop corrections to the processes at future…

High Energy Physics - Phenomenology · Physics 2017-07-10 Khiem Hong Phan

Feynman amplitudes at higher orders in perturbation theory generically have complex singular structures. Notwithstanding the emergence of many powerful new methods, the presence of infrared divergences poses significant challenges for their…

High Energy Physics - Phenomenology · Physics 2019-09-04 Charalampos Anastasiou , George Sterman

Advances in computational power and hardware efficiency have enabled tackling increasingly complex, high-dimensional problems. While artificial intelligence (AI) achieves remarkable results, the interpretability of high-dimensional…

Machine Learning · Computer Science 2025-03-11 Federico Tessari , Kunpeng Yao , Neville Hogan

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

The hypergeometric function method naturally provides the analytic expressions of scalar integrals from concerned Feynman diagrams in some connected regions of independent kinematic variables, also presents the systems of homogeneous linear…

High Energy Physics - Phenomenology · Physics 2018-01-15 Tai-Fu Feng , Chao-Hsi Chang , Jian-Bin Chen , Zhi-Hua Gu , Hai-Bin Zhang

We elucidate the vector space (twisted relative cohomology) that is Poincar\'e dual to the vector space of Feynman integrals (twisted cohomology) in general spacetime dimension. The pairing between these spaces - an algebraic invariant…

High Energy Physics - Theory · Physics 2022-01-05 Simon Caron-Huot , Andrzej Pokraka

A novel method, the Gaussian Integral Method (GIM), is presented for calculating void fractions in Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) simulations. GIM is versatile and applicable to various grid types, including…

Fluid Dynamics · Physics 2026-05-15 Alireza Kianimoqadam , Justin L. Lapp