Universal bound on the strong coupling scale of a gravitationally coupled massive spin-2 particle
Universal bound on the strong coupling scale of a gravitationally coupled massive spin-2 particle
复制标题
引力耦合大质量自旋2粒子强耦合尺度上的万有界
DOI：
--
复制
发表时间：
2018
影响因子：
5
通讯作者：
Kurt Hinterbichler
中科院分区：
文献类型：
--
作者：
James Bonifacio;Kurt Hinterbichler
我们发现了一个模型无关的上限上的强耦合标度的大质量自旋2粒子耦合到爱因斯坦引力。我们的方法是直接构建这些自由度的树级散射振幅，并使用它们来找到微扰么正性破坏的最大尺度。最高的尺度是$\Lambda_3=\left（m^2M_P\right）^{1/3}$，它被无重影的双引力所饱和。如果一个粒子的动力学项符号不正确，则强耦合标度可进一步提高到M_P，从而唯一地给出二次曲率引力的振幅。我们还讨论了与引力耦合的大质量高自旋粒子的推广。
We find a model-independent upper bound on the strong coupling scale for a massive spin-2 particle coupled to Einstein gravity. Our approach is to directly construct tree-level scattering amplitudes for these degrees of freedom and use them to find the maximum scale of perturbative unitarity violation. The highest scale is $\Lambda_3=\left(m^2M_P\right)^{1/3}$, which is saturated by ghost-free bigravity. The strong coupling scale can be further raised to $M_P$ if the kinetic term for one particle has the wrong sign, which uniquely gives the amplitudes of quadratic curvature gravity. We also discuss the generalization to massive higher-spin particles coupled to gravity.