arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2103.09832hep-thastro-ph.COgr-qc
收藏

宇宙学切割规则

Cosmological Cutting Rules

University of Cambridge(剑桥大学)

Scott Melville, Enrico Pajer

AI总结:

本文证明幺正性导致一套系统的“宇宙学切割规则”,将任意圈图的不连续性用低阶图表示,并应用于暴胀有效场论的单圈修正。

摘要:

我们宇宙中的原初扰动被认为具有量子起源,可以通过宇宙波函数(或等价地,宇宙学关联函数)来描述。因此,这些可观测量必须携带量子力学基本原理——幺正时间演化的印记。事实上,最近发现幺正性意味着树图波函数系数之间的一组无穷多关系,称为宇宙学光学定理。这里,我们展示幺正性导致一套系统的“宇宙学切割规则”,这些规则约束任意数量场和任意圈阶的波函数系数。这些规则将n圈图的不连续性用低阶图的不连续性表示,并将树图的不连续性用具有更少外场的树图的不连续性表示。我们的结果具有显著的普适性,即适用于任意质量、任意自旋的场在非常一般的FLRW时空背景下与Bunch-Davies真空的任意相互作用。作为一个应用,我们展示了暴胀有效场论中的单圈修正如何由树图计算固定,并讨论了相关的微扰幺正性界限。这些发现极大地扩展了利用幺正性自举宇宙学可观测量以及限制弯曲时空上一致有效场论空间的潜力。

英文摘要:

Primordial perturbations in our universe are believed to have a quantum origin, and can be described by the wavefunction of the universe (or equivalently, cosmological correlators). It follows that these observables must carry the imprint of the founding principle of quantum mechanics: unitary time evolution. Indeed, it was recently discovered that unitarity implies an infinite set of relations among tree-level wavefunction coefficients, dubbed the Cosmological Optical Theorem. Here, we show that unitarity leads to a systematic set of "Cosmological Cutting Rules" which constrain wavefunction coefficients for any number of fields and to any loop order. These rules fix the discontinuity of an n-loop diagram in terms of lower-loop diagrams and the discontinuity of tree-level diagrams in terms of tree-level diagrams with fewer external fields. Our results apply with remarkable generality, namely for arbitrary interactions of fields of any mass and any spin with a Bunch-Davies vacuum around a very general class of FLRW spacetimes. As an application, we show how one-loop corrections in the Effective Field Theory of inflation are fixed by tree-level calculations and discuss related perturbative unitarity bounds. These findings greatly extend the potential of using unitarity to bootstrap cosmological observables and to restrict the space of consistent effective field theories on curved spacetimes.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑