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Related papers: Two-Loop Computation in Superstring Theory

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Two-loop MHV amplitudes in planar ${\cal N} = 4$ supersymmetric Yang Mills theory are known to exhibit many intriguing forms of cluster-algebraic structure. We leverage this structure to upgrade the symbols of the eight- and nine-particle…

High Energy Physics - Theory · Physics 2021-07-14 John Golden , Andrew J. McLeod

We initiate the computation of the 2-loop quantum AdS_5 x S^5 string corrections on the example of a certain string configuration in S^5 related by an analytic continuation to a folded rotating string in AdS_5 in the ``long string'' limit.…

High Energy Physics - Theory · Physics 2009-09-17 R. Roiban , A. Tirziu , A. A. Tseytlin

This article displays a proof of concept of the mixed analytical/numerical method, presented in previous publications, to compute two-loop functions with up to five massive propagators in a scalar theory having three- and four-leg vertices…

High Energy Physics - Phenomenology · Physics 2021-09-15 J. Ph. Guillet , E. Pilon , Y. Shimizu , M. S. Zidi

The infrared singularities of gravitational amplitudes are one-loop exact, in that higher-loop divergences are characterized by the exponential of the one-loop divergence. We show that the contributions to SU(N) gauge-theory amplitudes that…

High Energy Physics - Theory · Physics 2015-06-12 Stephen G. Naculich , Horatiu Nastase , Howard J. Schnitzer

We generalize to the eleven-dimensional superparticle Berkovits' prescription for loop computations in the pure spinor approach to covariant quantization of the superstring. Using these ten- and eleven-dimensional results, we compute…

High Energy Physics - Theory · Physics 2009-11-10 L. Anguelova , P. A. Grassi , P. Vanhove

We report on the recent progress in computing the effective supergravity action from superstring scattering amplitudes beyond the tree approximation. We discuss the moduli-dependent string loop corrections to gauge, gravitational and Yukawa…

High Energy Physics - Theory · Physics 2007-05-23 I. Antoniadis , T. R. Taylor

We show how studying leading singularities of Feynman diagrams, when all momenta are complex, gives a simple way of writing multi-loop and multi-particle scattering amplitudes in N=4 super Yang-Mills. The simplicity of the method is…

High Energy Physics - Theory · Physics 2008-03-14 Freddy Cachazo

Using an iterative solution of rapidity evolution equations, we compute partonic $2\to 2$ gauge theory amplitudes at four loops in full colour up to the Next-to-Next-to-Leading Logarithms (NNLL) in the Regge limit. By contrasting the…

High Energy Physics - Phenomenology · Physics 2021-09-08 Giulio Falcioni , Einan Gardi , Calum Milloy , Leonardo Vernazza

We compute the two-loop contributions to the free energy in the null compactification of perturbative string theory at finite temperature. The cases of bosonic, Type II and heterotic strings are all treated. The calculation exploits an…

High Energy Physics - Theory · Physics 2008-11-26 Henry C. D. Cove , Richard J. Szabo

We investigate Yangian-invariant deformations of one-loop amplitudes in N = 4 super-Yang-Mills theory employing an algebraic representation of amplitudes. In this language, we reproduce the deformed massless box integral describing the…

High Energy Physics - Theory · Physics 2015-06-22 Johannes Broedel , Marius de Leeuw , Matteo Rosso

Calculation of amplitudes in perturbative quantum field theory involve large loop integrals. The complexity of those integrals, in combination with the large number of Feynman diagrams, make the calculations very difficult. Reduction…

High Energy Physics - Phenomenology · Physics 2015-06-05 Ronald H. P. Kleiss , Ioannis Malamos , Costas G. Papadopoulos , Rob Verheyen

We start a systematic investigation of the one-loop mass corrections to (super-)string massive higher-spin states. While the imaginary part of the relevant amplitudes are finite, being related to the width of the decay of the states into…

High Energy Physics - Theory · Physics 2026-03-13 Massimo Bianchi , Maurizio Firrotta , Lorenzo Grimaldi

The monodromy relations in string theory provide a powerful and elegant formalism to understand some of the deepest properties of tree-level field theory amplitudes, like the color-kinematics duality. This duality has been instrumental in…

High Energy Physics - Theory · Physics 2017-07-24 Piotr Tourkine , Pierre Vanhove

The non-minimal pure spinor formalism for the superstring is used to prove two new multiloop theorems which are related to recent higher-derivative $R^4$ conjectures of Green, Russo and Vanhove. The first theorem states that when $0<n<12$,…

High Energy Physics - Theory · Physics 2008-11-26 Nathan Berkovits

We outline the recent results on the two-loop electroweak contributions to the electron-electron scattering cross sections and asymmetries. Although the two-loop corrections are strongly suppressed relative to the one-loop corrections, they…

High Energy Physics - Phenomenology · Physics 2014-11-18 A. Aleksejevs , S. Barkanova , V. Zykunov

We consider the one-loop B^2h^3 and B^4h amplitudes in type II string theory, where B is the NS-NS two-form and h the graviton, and expand to lowest order in alpha'. After subtracting diagrams due to quartic terms in the effective action,…

High Energy Physics - Theory · Physics 2011-08-04 David M. Richards

Two-loop self-energy corrections to the bound-electron $g$ factor are investigated theoretically to all orders in the nuclear binding strength parameter $Z\alpha$. The separation of divergences is performed by dimensional regularization,…

Atomic Physics · Physics 2020-01-08 B. Sikora , V. A. Yerokhin , N. S. Oreshkina , H. Cakir , C. H. Keitel , Z. Harman

We study the bispectrum of large-scale structure in the EFTofLSS including corrections up to two-loop. We derive an analytic result for the double-hard limit of the two-loop correction, and show that the UV-sensitivity can be absorbed by…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-15 Tobias Baldauf , Mathias Garny , Petter Taule , Theo Steele

We study the odd spin structure contributions to the multiloop amplitudes of light-cone gauge superstring field theory. We show that they coincide with the amplitudes in the conformal gauge with two of the vertex operators chosen to be in…

High Energy Physics - Theory · Physics 2018-04-04 Nobuyuki Ishibashi , Koichi Murakami

Two-loop corrections to scattering amplitudes are crucial theoretical input for collider physics. Recent years have seen tremendous advances in computing Feynman integrals, scattering amplitudes, and cross sections for five-particle…

High Energy Physics - Theory · Physics 2022-03-30 Johannes Henn , Tiziano Peraro , Yingxuan Xu , Yang Zhang