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Related papers: One-loop N=8 supergravity coefficients from N=4 su…

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We propose a new, twistor string theory inspired formalism to calculate loop amplitudes in N=4 super Yang-Mills theory. In this approach, maximal helicity violating (MHV) tree amplitudes of N=4 super Yang-Mills are used as vertices, using…

High Energy Physics - Theory · Physics 2010-04-05 Andreas Brandhuber , Bill Spence , Gabriele Travaglini

We characterise the one-loop amplitudes for N=6 and N=4 supergravity in four dimensions. For N=6 we find that the one-loop n-point amplitudes can be expanded in terms of scalar box and triangle functions only. This simplification is…

High Energy Physics - Theory · Physics 2011-09-22 David C. Dunbar , James H. Ettle , Warren B. Perkins

We study the perturbative expansion of N=8 supergravity in four dimensions from the viewpoint of the ``no-triangle'' hypothesis, which states that one-loop graviton amplitudes in N=8 supergravity only contain scalar box integral functions.…

High Energy Physics - Theory · Physics 2009-11-11 N. E. J. Bjerrum-Bohr , David C. Dunbar , Harald Ita , Warren B. Perkins , Kasper Risager

We compute the symbol of the two-loop five-point amplitude in $\mathcal N=8$ supergravity. We write an ansatz for the amplitude whose rational prefactors are based on not only 4-dimensional leading singularities, but also $d$-dimensional…

High Energy Physics - Theory · Physics 2019-03-27 Samuel Abreu , Lance J. Dixon , Enrico Herrmann , Ben Page , Mao Zeng

In this paper we discuss in detail computational methods and new results for one-loop virtual corrections to N = 4 super Yang-Mills scattering amplitudes calculated to all orders in epsilon, the dimensional regularization parameter. It is…

High Energy Physics - Theory · Physics 2015-03-19 Robert M. Schabinger

The collinear factorization properties of two-loop scattering amplitudes in dimensionally-regulated N=4 super-Yang-Mills theory suggest that, in the planar ('t Hooft) limit, higher-loop contributions can be expressed entirely in terms of…

High Energy Physics - Theory · Physics 2010-11-15 C. Anastasiou , Z. Bern , L. Dixon , D. A. Kosower

We argue that the scattering amplitudes in the maximally supersymmetric N=4 super-Yang-Mills theory possess a new symmetry which extends the previously discovered dual conformal symmetry. To reveal this property we formulate the scattering…

High Energy Physics - Theory · Physics 2009-12-22 J. M. Drummond , J. Henn , G. P. Korchemsky , E. Sokatchev

String theory implies that field theories containing gravity are in a certain sense `products' of gauge theories. We make this product structure explicit up to two loops for the relatively simple case of N=8 supergravity four-point…

High Energy Physics - Theory · Physics 2010-11-15 Z. Bern , L. Dixon , D. C. Dunbar , M. Perelstein , J. S. Rozowsky

In these lectures I describe the remarkable ultraviolet behavior of N=8 supergravity, which through four loops is no worse than that of N=4 super-Yang-Mills theory (a finite theory). I also explain the computational tools that allow…

High Energy Physics - Theory · Physics 2015-03-17 Lance J. Dixon

By exploiting relations between gravity and gauge theories, we present two infinite sequences of one-loop n-graviton scattering amplitudes: the `maximally helicity-violating' amplitudes in N=8 supergravity, and the `all-plus' helicity…

High Energy Physics - Theory · Physics 2010-11-15 Z. Bern , L. Dixon , M. Perelstein , J. S. Rozowsky

In this letter, we exploit generalised unitarity in order to calculate the cut-constructible part of one-loop amplitudes in non-supersymmetric Yang-Mills theory. In particular, we rederive the n-gluon MHV amplitudes for both the adjacent…

High Energy Physics - Phenomenology · Physics 2010-02-03 Andreas Brandhuber , Massimiliano Vincon

We revisit the familiar construction of one-loop scattering amplitudes via generalized unitarity in light of the recently understood properties of loop integrands prior to their integration. We show how in any four-dimensional quantum field…

High Energy Physics - Theory · Physics 2013-03-21 Jacob L. Bourjaily , Simon Caron-Huot , Jaroslav Trnka

In this paper, we give the general expressions for a special series of tree amplitudes of the Yang-Mills theory. This series of amplitudes have two adjacent massless spin-1 particles with extra-dimensional momenta and any number of positive…

High Energy Physics - Theory · Physics 2019-10-08 Yang An , Yi Li

We review some recent additions to the tool-chest of techniques for finding compact integrand representations of multiloop gauge-theory amplitudes - including non-planar contributions - applicable for N=4 super-Yang-Mills in four and higher…

High Energy Physics - Theory · Physics 2015-05-27 John Joseph M. Carrasco , Henrik Johansson

We calculate form factors of half-BPS operators in N=4 super Yang-Mills theory at tree level and one loop using novel applications of recursion relations and unitarity. In particular, we determine the expression of the one-loop form factors…

High Energy Physics - Theory · Physics 2011-02-03 Andreas Brandhuber , Bill Spence , Gabriele Travaglini , Gang Yang

We define recursion relations for N = 8 supergravity amplitudes using a generalization of the on-shell diagrams developed for planar N = 4 super-Yang-Mills. Although the recursion relations generically give rise to non-planar on-shell…

High Energy Physics - Theory · Physics 2016-06-29 Paul Heslop , Arthur E. Lipstein

We examine the ultraviolet behaviour of supergravity theories as a function of dimension and number of supercharges. We do so by the computation of one and two-loop physical on-shell four point amplitudes. For maximal supergravity, our…

High Energy Physics - Theory · Physics 2007-05-23 Z. Bern , D. Dunbar , L. Dixon , B. Julia , M. Perelstien , J. Rozowsky , D. Seminara , M. Trigante

A study of the colour-ordered one-loop amplitudes in N=4 SYM reveals a surprising property: numerically, the amplitudes have an Approximately Universal form A^{1-loop}_n ~ A^{tree}_n \times U_n, where U_n is helicity independent. This form…

High Energy Physics - Theory · Physics 2009-03-27 David C. Dunbar , James H. Ettle , Warren B. Perkins

We review recent progress in computations of amplitudes in gauge theory and gravity. We compare the perturbative expansion of amplitudes in N=4 super Yang-Mills and N=8 supergravity and discuss surprising similarities.

High Energy Physics - Theory · Physics 2017-08-23 N. E. J. Bjerrum-Bohr , David C. Dunbar , Harald Ita

We establish an efficient polynomial-complexity algorithm for one-loop calculations, based on generalized $D$-dimensional unitarity. It allows automated computations of both cut-constructible {\it and} rational parts of one-loop scattering…

High Energy Physics - Phenomenology · Physics 2009-09-17 Walter T. Giele , Zoltan Kunszt , Kirill Melnikov