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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

These notes were given as lectures at the CERN Winter School on Supergravity, Strings and Gauge Theory 2010. We describe the structure of scattering amplitudes in gauge theories, focussing on the maximally supersymmetric theory to highlight…

High Energy Physics - Theory · Physics 2015-03-17 J. M. Drummond

We present a new method for calculating loops in cosmological perturbation theory. This method is based on approximating a $\Lambda$CDM-like cosmology as a finite sum of complex power-law universes. The decomposition is naturally achieved…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-25 Marko Simonović , Tobias Baldauf , Matias Zaldarriaga , John Joseph Carrasco , Juna A. Kollmeier

We use the duality between color and kinematics to simplify the construction of the complete four-loop four-point amplitude of N=4 super-Yang-Mills theory, including the nonplanar contributions. The duality completely determines the…

High Energy Physics - Theory · Physics 2012-10-17 Z. Bern , J. J. M. Carrasco , L. J. Dixon , H. Johansson , R. Roiban

Explicit expressions for one-loop five supergraviton scattering amplitudes in both type II superstring theories are determined by making use of the pure spinor formalism. The type IIB amplitude can be expressed in terms of a doubling of…

High Energy Physics - Theory · Physics 2015-06-16 Michael B. Green , Carlos R. Mafra , Oliver Schlotterer

The abundance of infrared singularities in gauge theories due to unresolved emission of massless particles (soft and collinear) represents the main difficulty in perturbative calculations. They are typically regularized in dimensional…

High Energy Physics - Phenomenology · Physics 2016-03-23 Roger J. Hernandez-Pinto , German F. R. Sborlini , German Rodrigo

We summarise the status of an intriguing new duality between planar maximally helicity violating scattering amplitudes and light-like Wilson loops in N=4 super Yang-Mills. In particular, we focus on the role played by (dual) conformal…

High Energy Physics - Theory · Physics 2022-10-05 Johannes Henn

In this talk, we review the basis of the loop-tree duality theorem, which allows to rewrite loop scattering amplitudes in terms of tree-level like objects. Since the loop measure is converted into a phase-space one, both virtual and real…

High Energy Physics - Phenomenology · Physics 2016-11-16 German F. R. Sborlini , Felix Driencourt-Mangin , Roger Hernandez-Pinto , German Rodrigo

We present novel techniques for the computation of three-loop four-parton scattering amplitudes in full color, non-planar gauge theories. We elaborate on how the analytic results for these amplitudes can be used to confirm the conjectured…

High Energy Physics - Phenomenology · Physics 2022-08-18 Amlan Chakraborty , Giulio Gambuti

We present a method for the computation of hepta-cuts of two loop scattering amplitudes. Four dimensional unitarity cuts are used to factorise the integrand onto the product of six tree-level amplitudes evaluated at complex momentum values.…

High Energy Physics - Phenomenology · Physics 2012-04-18 Simon Badger , Hjalte Frellesvig , Yang Zhang

In this paper, we generalize the unitarity method to two-loop diagrams and use it to discuss the integral bases of reduction. To test out method, we focus on the four-point double-box diagram as well as its related daughter diagrams, i.e.,…

High Energy Physics - Theory · Physics 2015-06-18 Bo Feng , Jun Zhen , Rijun Huang , Kang Zhou

Scattering amplitudes at loop level can be reduced to a basis of linearly independent Feynman integrals. The integral coefficients are extracted from generalized unitarity cuts which define algebraic varieties. The topology of an algebraic…

High Energy Physics - Theory · Physics 2015-06-03 Mads Sogaard , Yang Zhang

The recent proposal [1911.06318, 2010.07861] of implementing electric-magnetic duality rotation at the level of perturbative scattering amplitudes and its generalisation to gravitational context where usual gravitational mass is rotated to…

High Energy Physics - Theory · Physics 2021-03-08 Jung-Wook Kim , Myungbo Shim

I derive the set of recurrence relations between the amplitudes of multiparticle production at threshold in the standard large-N limit of the O(N)-symmetric phi^4$ theory which sums all relevant diagrams with arbitrary number of loops. I…

High Energy Physics - Phenomenology · Physics 2013-11-13 Yu. Makeenko

We calculate one-loop scattering amplitudes in N=4 super Yang-Mills theory away from the origin of the moduli space and demonstrate that the results are extremely simple, in much the same way as in the conformally invariant theory.…

High Energy Physics - Theory · Physics 2015-02-23 Robert M. Schabinger

The calculation of scattering amplitudes in Yang-Mills theory at loop level is important for the analysis of background processes at particle colliders as well as our understanding of perturbation theory at the quantum level. We present…

High Energy Physics - Theory · Physics 2013-05-30 Rutger H. Boels , Reinke Sven Isermann

Causal set theory is an approach to quantum gravity in which spacetime is fundamentally discrete at the Planck scale and takes the form of a Lorentzian lattice, or "causal set", from which continuum spacetime emerges in a large-scale…

High Energy Physics - Theory · Physics 2024-05-15 Emma Albertini , Fay Dowker , Arad Nasiri , Stav Zalel

Recent works have explored how scattering amplitudes in quantum self-dual Yang-Mills theory and self-dual gravity can be interpreted as resulting from an anomaly, as first proposed by W. Bardeen. We study this problem in the…

High Energy Physics - Theory · Physics 2024-01-10 Ricardo Monteiro , Ricardo Stark-Muchão , Sam Wikeley

Though the one-loop amplitudes of the Higgs boson to massless gauge bosons are finite because there is no direct interaction at tree-level in the Standard Model, a well-defined regularization scheme is still required for their correct…

High Energy Physics - Phenomenology · Physics 2018-03-22 Felix Driencourt-Mangin , German Rodrigo , German F. R. Sborlini

High-energy colliders, such as the Large Hadron Collider (LHC) at CERN, are genuine quantum machines, so, in line with Richard Feynman's original motivation for Quantum Computing, the scattering processes that take place there are natural…

High Energy Physics - Phenomenology · Physics 2026-01-05 Germán Rodrigo