论文标题
两层四环散射幅度
The Two-Loop Four-Graviton Scattering Amplitudes
论文作者
论文摘要
我们介绍了爱因斯坦重力中两环四环散射幅度的分析形式。为了消除紫外线差异，我们在Riemann曲率张量中包括反转二次和立方体。两循环数值单位性方法用于处理相互作用的挑战性动量依赖性。我们利用振幅集成的代数特性，以将其映射到Feynman积分的最小基础上。分析表达式是从振幅的数值评估中获得的。最后，我们表明，四颗粒散射可观察到的依赖于比天真预期的更少的耦合。
We present the analytic form of the two-loop four-graviton scattering amplitudes in Einstein gravity. To remove ultraviolet divergences we include counterterms quadratic and cubic in the Riemann curvature tensor. The two-loop numerical unitarity approach is used to deal with the challenging momentum dependence of the interactions. We exploit the algebraic properties of the integrand of the amplitude in order to map it to a minimal basis of Feynman integrals. Analytic expressions are obtained from numerical evaluations of the amplitude. Finally, we show that four-graviton scattering observables depend on fewer couplings than naively expected.
