论文标题
宇宙学的自举:来自对称性和分解的旋转相关器
The Cosmological Bootstrap: Spinning Correlators from Symmetries and Factorization
论文作者
论文摘要
我们将宇宙学的引导程序扩展到涉及带有自旋的无质量颗粒的相关器。在De Sitter空间中,这些相关因子受对称和位置的约束。特别是,de Sitter异构体在时空的未来边界上变成了形式的对称性,这反映在边界相关器必须满足的一组病房身份中。我们通过在标量种子解决方案上与重量转移操作员作用来解决这些病房的身份。使用这种重量转移方法,我们带有与共同耦合标量的无质量自旋1和自旋2场的三分和四点相关器。树级交换引起的四点函数在尤其是运动构构中,这些奇异性的系数满足某些因素化属性。我们表明,在许多情况下,这些分解限制了唯一固定相关因子的结构,而无需解决保形病房的身份。无质量旋转颗粒的局部局部性的附加约束表现为边界上的电流保护。我们发现,当S,T和U通道相互关联时,四点函数仅满足当前的保护,从而导致对理论中保守电流与其他操作员之间的耦合的非平凡约束。对于Spin-1电流,这意味着电荷保护,而对于Spin-2电流,我们从纯粹的边界角度恢复了等效原理。对于多个SPIN-1字段,我们恢复了Yang-Mills理论的结构。最后,我们将我们的方法应用于缓慢的膨胀通货膨胀,并得出了一些与现象学相关的标量调整的三点函数。
We extend the cosmological bootstrap to correlators involving massless particles with spin. In de Sitter space, these correlators are constrained both by symmetries and by locality. In particular, the de Sitter isometries become conformal symmetries on the future boundary of the spacetime, which are reflected in a set of Ward identities that the boundary correlators must satisfy. We solve these Ward identities by acting with weight-shifting operators on scalar seed solutions. Using this weight-shifting approach, we derive three- and four-point correlators of massless spin-1 and spin-2 fields with conformally coupled scalars. Four-point functions arising from tree-level exchange are singular in particular kinematic configurations, and the coefficients of these singularities satisfy certain factorization properties. We show that in many cases these factorization limits fix the structure of the correlators uniquely, without having to solve the conformal Ward identities. The additional constraint of locality for massless spinning particles manifests itself as current conservation on the boundary. We find that the four-point functions only satisfy current conservation if the s, t, and u-channels are related to each other, leading to nontrivial constraints on the couplings between the conserved currents and other operators in the theory. For spin-1 currents this implies charge conservation, while for spin-2 currents we recover the equivalence principle from a purely boundary perspective. For multiple spin-1 fields, we recover the structure of Yang-Mills theory. Finally, we apply our methods to slow-roll inflation and derive a few phenomenologically relevant scalar-tensor three-point functions.