论文标题
$ \ Mathcal {n} = 7 $ shell图和超级振幅在动量扭曲器空间中
$\mathcal{N}=7$ On-Shell Diagrams and Supergravity Amplitudes in Momentum Twistor Space
论文作者
论文摘要
我们在$ \ Mathcal {n} = 7 $ supergravity中得出了树级散射幅度的壳图递归。这些图是根据晶格的积分和动量扭曲器评估的，将动量扭曲空间中霍奇斯的先前结果推广到非MHV振幅。特别是，我们根据$ \ MATHCAL {n} = 7 $ r-Invariants的五分和六点NMHV振幅，类似于$ \ Mathcal {n} = 4 $ super-yang-mills，这使得失败的poles的取消变得更加透明。高于5分，这需要定义动量扭曲器相对于外部动量的不同顺序。
We derive an on-shell diagram recursion for tree-level scattering amplitudes in $\mathcal{N}=7$ supergravity. The diagrams are evaluated in terms of Grassmannian integrals and momentum twistors, generalising previous results of Hodges in momentum twistor space to non-MHV amplitudes. In particular, we recast five and six-point NMHV amplitudes in terms of $\mathcal{N}=7$ R-invariants analogous to those of $\mathcal{N}=4$ super-Yang-Mills, which makes cancellation of spurious poles more transparent. Above 5-points, this requires defining momentum twistors with respect to different orderings of the external momenta.
