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Related papers: Gravity loop integrands from the ultraviolet

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The duality between color and kinematics enables the construction of multiloop gravity integrands directly from corresponding gauge-theory integrands. This has led to new nontrivial insights into the structure of gravity theories, including…

High Energy Physics - Theory · Physics 2016-05-18 Zvi Bern , Scott Davies , Josh Nohle

We show, for previously uncalculated examples containing a uniform mass in the loop, that it is possible to obtain complete massive one-loop gauge theory amplitudes solely from unitarity and known ultraviolet or infrared mass singularities.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Z. Bern , A. G. Morgan

We discuss the calculation of one-loop amplitudes in N=8 supergravity using MHV diagrams. In contrast to MHV amplitudes of gluons in Yang-Mills, tree-level MHV amplitudes of gravitons are not holomorphic in the spinor variables. In order to…

High Energy Physics - Theory · Physics 2008-11-26 Adele Nasti , Gabriele Travaglini

A first quantised approach to loop amplitudes based on the pure spinor particle is applied to the systematics of four-particle amplitudes in maximally supersymmetric field theories. Counting of fermionic zero modes allows the identification…

High Energy Physics - Theory · Physics 2011-03-28 Jonas Bjornsson , Michael B. Green

We analyze the critical ultraviolet behaviour of the four-graviton amplitude in N=8 supergravity to all order in perturbation. We use the Bern-Carrasco-Johansson diagrammatic expansion for N=8 supergravity multiloop amplitudes, where…

High Energy Physics - Theory · Physics 2010-04-15 Pierre Vanhove

We present the full two-loop four-graviton amplitudes in N=4,5,6 supergravity. These results were obtained using the double-copy structure of gravity, which follows from the recently conjectured color-kinematics duality in gauge theory. The…

High Energy Physics - Theory · Physics 2015-05-30 C. Boucher-Veronneau , L. J. Dixon

The decomposition of a one-loop scattering amplitude into elementary functions with rational coefficients introduces spurious singularities which afflict individual coefficients but cancel in the complete amplitude. These cancellations…

High Energy Physics - Theory · Physics 2013-05-29 David C. Dunbar , James H. Ettle , Warren B. Perkins

We present the explicit expressions in N=8 supergravity for the bosonic 4-particle tree and 1-loop amplitudes including vectors and scalars. We also present the candidate 4-point UV divergences in a form of helicity amplitudes,…

High Energy Physics - Theory · Physics 2009-09-29 Renata Kallosh , Ching Hua Lee , Tomas Rube

According to the recent pure spinor analysis of the UV divergences by Karlsson, there are no divergent 1PI structures beyond 6 loops in D=4 N=8 supergravity. In combination with the common expectation that the UV divergences do not appear…

High Energy Physics - Theory · Physics 2014-12-23 Renata Kallosh

The scattering equations on the Riemann sphere give rise to remarkable formulae for tree-level gauge theory and gravity amplitudes. Adamo, Casali and Skinner conjectured a one-loop formula for supergravity amplitudes based on scattering…

High Energy Physics - Theory · Physics 2015-09-23 Yvonne Geyer , Lionel Mason , Ricardo Monteiro , Piotr Tourkine

In this article a first step is made towards the extension of Britto-Cachazo-Feng-Witten (BCFW) tree level on-shell recursion relations to integrands and integrals of scattering amplitudes to arbitrary loop order. Surprisingly, it is shown…

High Energy Physics - Theory · Physics 2010-11-30 Rutger H. Boels

Recently, an explicit, recursive formula for the all-loop integrand of planar scattering amplitudes in N=4 SYM has been described, generalizing the BCFW formula for tree amplitudes, and making manifest the Yangian symmetry of the theory.…

High Energy Physics - Theory · Physics 2015-05-20 Nima Arkani-Hamed , Jacob L. Bourjaily , Freddy Cachazo , Jaroslav Trnka

We study on-shell diagrams for gravity theories with any number of supersymmetries and find a compact Grassmannian formula in terms of edge variables of the graphs. Unlike in gauge theory where the analogous form involves only…

High Energy Physics - Theory · Physics 2016-12-21 Enrico Herrmann , Jaroslav Trnka

We show that the four-loop four-point amplitudes of N = 5 supergravity are ultraviolet finite in four dimensions, contrary to expectations based on supersymmetry and duality-symmetry arguments. We explain why the diagrams of any covariant…

High Energy Physics - Theory · Physics 2014-11-19 Zvi Bern , Scott Davies , Tristan Dennen

We develop an iterative method for constructing four-dimensional generalized unitarity cuts in $\mathcal{N} = 2$ supersymmetric Yang-Mills (SYM) theory coupled to fundamental matter hypermultiplets ($\mathcal{N} = 2$ SQCD). For iterated…

High Energy Physics - Theory · Physics 2019-10-08 Gregor Kälin , Gustav Mogull , Alexander Ochirov

We construct an infinite class of new ultraviolet-complete four-graviton scattering amplitudes that reduce to Einstein gravity at low energies, vanish at high energies, are meromorphic, and exhibit a triple-product structure ${\cal…

High Energy Physics - Theory · Physics 2022-07-20 Yu-tin Huang , Grant N. Remmen

We describe a systematic approach to the construction of loop-integrand bases at arbitrary loop-order, sufficient for the representation of general quantum field theories. We provide a graph-theoretic definition of `power-counting' for…

High Energy Physics - Theory · Physics 2020-12-30 Jacob L. Bourjaily , Enrico Herrmann , Cameron Langer , Jaroslav Trnka

We calculate one-loop scattering amplitudes for gravitons and two-forms in dimensions greater than four. The string based Kawai-Lewellen-Tye relationships allow gravitons and two-forms to be treated in a unified manner. We use the results…

High Energy Physics - Theory · Physics 2017-01-25 David C. Dunbar , Nicolaus W. P. Turner

We introduce a constructive method for defining a global loop-integrand basis for scattering amplitudes, encompassing both planar and nonplanar contributions. Our approach utilizes a graph-based framework to establish a well-defined,…

High Energy Physics - Theory · Physics 2024-11-26 Zvi Bern , Enrico Herrmann , Radu Roiban , Michael S. Ruf , Mao Zeng

We propose a procedure to determine the moduli-space integrands of loop-level superstring amplitudes for massless external states in terms of the field theory limit. We focus on the type II superstring. The procedure is to: (i) take a…

High Energy Physics - Theory · Physics 2021-11-19 Yvonne Geyer , Ricardo Monteiro , Ricardo Stark-Muchão