Cutting cosmological correlators
Cutting cosmological correlators
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DOI：
10.1088/1475-7516/2021/08/003
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发表时间：
2021-04
影响因子：
6.4
通讯作者：
H. Goodhew;Sadra Jazayeri;Mang Hei Gordon Lee;E. Pajer
中科院分区：
文献类型：
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作者：
H. Goodhew;Sadra Jazayeri;Mang Hei Gordon Lee;E. Pajer
我们宇宙的初始条件以经典概率分布的形式出现在我们面前，我们用宇宙学观测来探测它。在当前的主导范式中，这种概率分布来自于宇宙的量子力学波函数。在这里，我们要问的是，量子力学对晚期可观测量的影响是什么。我们表明，么正时间演化的要求，通俗地说是概率守恒，固定了波函数及其编码的所有宇宙学相关器的分析结构。特别是，我们在微扰理论中推导出一组无限的单切规则，推广了宇宙光学定理，并将任何树级n点函数的某些不连续性与低点函数的不连续性联系起来。我们的规则与最近推导出的宇宙切割规则密切相关，但又有所不同。他们遵循从选择的Bunch-Davies真空和一个简单的属性（散装散装）传播和惊人的一般：我们证明，他们是有效的领域与线性色散关系和任何质量，任何整数自旋和任意本地相互作用与任何数量的衍生物。他们也适用于一般FLRW时空承认邦奇戴维斯真空，包括德西特，慢卷膨胀，幂律宇宙学，甚至共振振荡轴子monodromy。我们验证了一些非平凡的例子，包括四个无质量标量交换一个巨大的标量，相关的宇宙对撞机物理，四个引力子交换引力子，和标量五点函数的单切规则。
The initial conditions of our universe appear to us in the form of a classical probability distribution that we probe with cosmological observations. In the current leading paradigm, this probability distribution arises from a quantum mechanical wavefunction of the universe. Here we ask what the imprint of quantum mechanics is on the late time observables. We show that the requirement of unitary time evolution, colloquially the conservation of probabilities, fixes the analytic structure of the wavefunction and of all the cosmological correlators it encodes. In particular, we derive in perturbation theory an infinite set of single-cut rules that generalize the Cosmological Optical Theorem and relate a certain discontinuity of any tree-level n-point function to that of lower-point functions. Our rules are closely related to, but distinct from the recently derived Cosmological Cutting Rules. They follow from the choice of the Bunch-Davies vacuum and a simple property of the (bulk-to-bulk) propagator and are astoundingly general: we prove that they are valid for fields with a linear dispersion relation and any mass, any integer spin and arbitrary local interactions with any number of derivatives. They also apply to general FLRW spacetimes admitting a Bunch-Davies vacuum, including de Sitter, slow-roll inflation, power-law cosmologies and even resonant oscillations in axion monodromy. We verify the single-cut rules in a number of non-trivial examples, including four massless scalars exchanging a massive scalar, as relevant for cosmological collider physics, four gravitons exchanging a graviton, and a scalar five-point function.