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Related papers: Uniqueness from locality and BCFW shifts

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A proof is given of the formula, recently proposed by Cachazo, He and Yuan (CHY) for gluon tree amplitudes in pure Yang-Mills theory in arbitrary dimension. The approach is to first establish the corresponding result for massless $\phi^3$…

High Energy Physics - Theory · Physics 2015-06-18 Louise Dolan , Peter Goddard

We use generalized unitarity at the integrand-level to directly construct local, manifestly dual-conformally invariant formulae for all two-loop scattering amplitudes in planar, maximally supersymmetric Yang-Mills theory (SYM). This…

High Energy Physics - Theory · Physics 2017-05-22 Jacob L. Bourjaily , Jaroslav Trnka

On-shell constructibility is redefining our understanding of perturbative quantum field theory. The tree-level S-matrix of constructible theories is completely determined by a set of recurrence relations and a reduced number of scattering…

High Energy Physics - Theory · Physics 2019-10-16 Raúl Carballo-Rubio , Francesco Di Filippo , Nathan Moynihan

In this note, we address the question of whether locality, unitarity, and newly discovered hidden zeros can completely determine tree-level amplitudes, from the perspective of soft limit. We reconstruct the single-soft theorems of tree YM…

High Energy Physics - Theory · Physics 2026-04-09 Kang Zhou

In recent years, the BCFW construction provided a very powerful tool for computing scattering amplitudes as well as it shed light on the perturbation theory structure. In this talk, we discuss the long-standing issue of the boundary term…

High Energy Physics - Theory · Physics 2016-01-20 Paolo Benincasa

We investigate the new soft graviton theorem recently proposed in arXiv:1404.4091. We use the CHY formula to prove this universal formula for both Yang-Mills theory and gravity scattering amplitudes at tree level in arbitrary dimension.

High Energy Physics - Theory · Physics 2014-09-10 Burkhard U. W. Schwab , Anastasia Volovich

In this short note I show that the soft limit for colour-ordered tree-level Yang-Mills amplitudes contains a sub-leading divergent term analogous to terms found recently by Cachazo and Strominger for tree-level gravity amplitudes.

High Energy Physics - Theory · Physics 2015-06-19 Eduardo Casali

By means of a kinematic analysis of tree level graviton amplitudes we find, at least through six points, that the reason of their decompositon as a sum over products of Yang-Mills amplitudes is on-shell gauge invariance and unitarity. As a…

High Energy Physics - Theory · Physics 2020-02-19 Luiz Antonio Barreiro , Ricardo Medina

The massless QCD Lagrangian is conformally invariant and, as a consequence, so are the tree-level scattering amplitudes. However, the implications of this powerful symmetry at loop level are only beginning to be explored systematically.…

High Energy Physics - Theory · Physics 2020-03-18 Johannes Henn , Bláithín Power , Simone Zoia

We conjecture that the leading two-derivative tree-level amplitudes for gluons and gravitons can be derived from gauge invariance together with mild assumptions on their singularity structure. Assuming locality (that the singularities are…

High Energy Physics - Theory · Physics 2018-06-13 Nima Arkani-Hamed , Laurentiu Rodina , Jaroslav Trnka

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

In this paper, we extend the method proposed in \cite{Arkani-Hamed:2024fyd} for deriving soft theorems of amplitudes, which relies exclusively on factorization properties including conventional factorizations on physical poles, as well as…

High Energy Physics - Theory · Physics 2026-05-05 Kang Zhou

We study tree-level celestial amplitudes in Yang-Mills theory -- Mellin transforms of multi-gluon scattering amplitudes that convert them into the correlators of conformal primary fields on two-dimensional celestial sphere. By using purely…

High Energy Physics - Theory · Physics 2019-06-26 Wei Fan , Angelos Fotopoulos , Tomasz R. Taylor

Tree level scattering amplitudes in N=4 super Yang-Mills theory are almost, but not exactly invariant under the free action of the N=4 superconformal algebra. What causes the non-invariance is the holomorphic anomaly at poles where external…

High Energy Physics - Theory · Physics 2009-11-11 Till Bargheer , Niklas Beisert , Wellington Galleas , Florian Loebbert , Tristan McLoughlin

In this letter we derive new expressions for tree-level graviton amplitudes in $\mathcal{N}=8$ supergravity from BCFW recursion relations combined with new types of bonus relations. These bonus relations go beyond the famous $1/z^2$…

High Energy Physics - Theory · Physics 2023-09-13 Shruti Paranjape , Jaroslav Trnka

We use the recently developed massive spinor-helicity formalism [1] of Arkani- Hamed et al. to propose a new class of recursion relations for tree-level amplitudes in gauge theories. These relations are based on a combined complex…

High Energy Physics - Theory · Physics 2021-05-13 Sourav Ballav , Arkajyoti Manna

The leading singularities of one-loop scattering amplitudes in planar $\mathcal{N}=4$ super Yang-Mills theory are known to factorise into products of tree-level amplitudes, and this can be seen from a number of different perspectives e.g.…

High Energy Physics - Theory · Physics 2026-02-23 James Drummond , Matthew Rochford , Rowan Wright

Building on our proposal in arXiv:2405.06629, we present in detail the construction of the extended phase space for Yang-Mills at null infinity, containing the asymptotic symmetries and the charges responsible for sub$^n$-leading soft…

High Energy Physics - Theory · Physics 2024-11-01 Silvia Nagy , Javier Peraza , Giorgio Pizzolo

Using the double-copy construction of Yang-Mills-Einstein theories formulated in our earlier work, we obtain compact presentations for single-trace Yang-Mills-Einstein tree amplitudes with up to five external gravitons and an arbitrary…

High Energy Physics - Theory · Physics 2017-08-25 Marco Chiodaroli , Murat Gunaydin , Henrik Johansson , Radu Roiban

We investigate the soft decomposition of tree-level gluon amplitudes with split-helicity configurations. First, we show how any split-helicity amplitude can be fully fixed from inverse soft limit using BCFW calculation. We show how the…

High Energy Physics - Theory · Physics 2025-12-09 Andriniaina Narindra Rasoanaivo , Fanomezantsoa Arlivah Andriantsarafara