scholarly journals Subsubleading soft graviton symmetry and MHV graviton scattering amplitudes

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Shamik Banerjee ◽  
Sudip Ghosh ◽  
Sai Satyam Samal

Abstract In [8] it was shown that supertranslation and $$ \overline{\mathrm{SL}\left(2,\mathbb{C}\right)} $$ SL 2 ℂ ¯ current algebra symmetries, corresponding to leading and subleading soft graviton theorems, are enough to determine the tree level MHV graviton scattering amplitudes. In this note we clarify the role of subsubleading soft graviton theorem in this context.

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Shamik Banerjee ◽  
Sudip Ghosh

Abstract We show that the Mellin transform of an n-point tree level MHV gluon scattering amplitude, also known as the celestial amplitude in pure Yang-Mills theory, satisfies a system of (n−2) linear first order partial differential equations corresponding to (n−2) positive helicity gluons. Although these equations closely resemble Knizhnik-Zamoldochikov equations for SU(N) current algebra there is also an additional “correction” term coming from the subleading soft gluon current algebra. These equations can be used to compute the leading term in the gluon-gluon OPE on the celestial sphere. Similar equations can also be written down for the momentum space tree level MHV scattering amplitudes. We also propose a way to deal with the non closure of subleading current algebra generators under commutation. This is then used to compute some subleading terms in the mixed helicity gluon OPE.


2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Hongliang Jiang

Abstract Celestial amplitude is a new reformulation of momentum space scattering amplitudes and offers a promising way for flat holography. In this paper, we study the celestial amplitudes in $$ \mathcal{N} $$ N = 4 Super-Yang-Mills (SYM) theory aiming at understanding the role of superconformal symmetry in celestial holography. We first construct the superconformal generators acting on the celestial superfield which assembles all the on-shell fields in the multiplet together in terms of celestial variables and Grassmann parameters. These generators satisfy the superconformal algebra of $$ \mathcal{N} $$ N = 4 SYM theory. We also compute the three-point and four-point celestial super-amplitudes explicitly. They can be identified as the conformal correlation functions of the celestial superfields living at the celestial sphere. We further study the soft and collinear limits which give rise to the super-Ward identity and super-OPE on the celestial sphere, respectively. Our results initiate a new perspective of understanding the well-studied $$ \mathcal{N} $$ N = 4 SYM amplitudes via 2D celestial conformal field theory.


1989 ◽  
Vol 04 (21) ◽  
pp. 2063-2071
Author(s):  
GEORGE SIOPSIS

It is shown that the contact term discovered by Wendt is sufficient to ensure finiteness of all tree-level scattering amplitudes in Witten’s field theory of open superstrings. Its inclusion in the action also leads to a gauge-invariant theory. Thus, no additional higher-order counterterms in the action are needed.


1994 ◽  
Vol 09 (18) ◽  
pp. 1695-1700 ◽  
Author(s):  
O.M. DEL CIMA

One discusses the tree-level unitarity and presents asymptotic behavior of scattering amplitudes for three-dimensional gauge-invariant models where complex Chern- Simons-Maxwell fields (with and without a Proca-like mass) are coupled to an Abelian gauge field.


2021 ◽  
Vol 2021 (12) ◽  
Author(s):  
Maor Ben-Shahar ◽  
Max Guillen

Abstract Using the pure spinor master action for 10D super-Yang-Mills in the gauge b0V = QΞ, tree-level scattering amplitudes are calculated through the perturbiner method, and shown to match those obtained from pure spinor CFT techniques. We find kinematic numerators made of nested b-ghost operators, and show that the Siegel gauge condition b0V = 0 gives rise to color-kinematics duality satisfying numerators whose Jacobi identity follows from the Jacobi identity of a kinematic algebra.


2019 ◽  
Vol 10 (1) ◽  
pp. 116
Author(s):  
Muhammad Daryadi A ◽  
Medi Hendra ◽  
Nova Hariani

AbstractThis study aimed to determine the composition and structure of Semayang forest and the Importance Value Index (IVI) of riparian forest in its role of reducing the wave rate. The method used is multilevel plot method of 20x20 m for sampling of tree level, 5x5 m for sapling level and 2x2 m for seedling level. The result showed that the highest Importance Value Index at tree level was dominated by 3 species, they were L. javanicum (101,663), M. speciosa (76,201) and G. renghas (65,962). At sapling level dominated by P. indica (102,990). At seedling level dominated by M. pigra (95,004)andP. brevistipitata (70,109). In addition, Semayang riparian forest has an ecological function as a wave retaining. It can be seen based on the vegetation density and horizontal structure of species that make up the forest. Vegetation density is predicted to reduce the rate of Semayang lake waves that occur during flood season. Keywords: Composition and Structure, Riparian Forest, Semayang Lake. 


2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Vittorio Del Duca ◽  
Claude Duhr ◽  
Rayan Haindl ◽  
Achilleas Lazopoulos ◽  
Martin Michel

Abstract We compute in conventional dimensional regularisation the tree-level splitting amplitudes for a gluon parent which splits into four collinear partons. This is part of the universal infrared behaviour of the QCD scattering amplitudes at next-to-next-to-next-to-leading order (N3LO) in the strong coupling constant. Combined with our earlier results for a quark parent, this completes the set of tree-level splitting amplitudes required at this order. We also study iterated collinear limits where a subset of the four collinear partons become themselves collinear.


2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
David Stefanyszyn ◽  
Jakub Supeł

Abstract In a recent paper [1], three-particle interactions without invariance under Lorentz boosts were constrained by demanding that they yield tree-level four-particle scattering amplitudes with singularities as dictated by unitarity and locality. In this brief note, we show how to obtain an independent verification and consistency check of these boostless bootstrap results using BCFW momentum shifts. We point out that the constructibility criterion, related to the behaviour of the deformed amplitude at infinite BCFW parameter z, is not strictly necessary to obtain non-trivial constraints for the three-particle interactions.


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