论文标题
朝向重力：NMHV重力振幅的新表达式
Towards the Gravituhedron: New Expressions for NMHV Gravity Amplitudes
论文作者
论文摘要
在本文中，我们提出了N-Point NMHV树级重力振幅的新表达式。我们介绍了一种分解图的方法，这是Yang-Mills理论中R不变的简单图形表示。我们定义了称为G不变的重力类似物，并根据这些对象扩展了NMHV重力振幅。我们提供NMHV重力幅度的明确公式，就G-不变性而言，最多八个点，并给出任何数量的一般定义。我们讨论与BCFW表示的联系，大动量转移下的特殊行为，动量扭曲器的作用以及复杂的伪造杆取消的网络。由于R-Invariants与Yang-Mills振幅的（树级）扩展之间的连接，我们推测重力振幅的新扩展应与假定的raverituhedron几何形状的三角测量相对应。
In this paper, we present new expressions for n-point NMHV tree-level gravity amplitudes. We introduce a method of factorization diagrams which is a simple graphical representation of R-invariants in Yang-Mills theory. We define the gravity analogues which we call G-invariants, and expand the NMHV gravity amplitudes in terms of these objects. We provide explicit formulas of NMHV gravity amplitudes up to eight points in terms of G-invariants, and give the general definition for any number of points. We discuss the connection to BCFW representation, special behavior under large momentum shift, the role of momentum twistors and the intricate web of spurious poles cancelation. Because of the close connection between R-invariants and the (tree-level) Amplituhedron for Yang-Mills amplitudes, we speculate that the new expansion for gravity amplitudes should correspond to the triangulation of the putative Gravituhedron geometry.
