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 2009.03047hep-th
收藏

Steinmann关系和宇宙的波函数

Steinmann Relations and the Wavefunction of the Universe

Paolo Benincasa, Andrew J. McLeod, Cristian Vergu

摘要:

因果性和么正性的物理原理对平坦空间S-矩阵的解析结构提出了严格的限制。特别是,这些原则引起的斯坦曼关系,它要求的双重不连续性的散射振幅部分重叠的动量通道消失。相反,在宇宙学尺度上,因果关系和么正性的印记一般不太好理解-宇宙的波函数存在于未来的类空边界上,并将所有的时间演化整合出来。在目前的工作中,我们展示了如何从宇宙波函数的结构中出现平坦空间的斯坦曼关系,并推导出适用于波函数本身的类似关系。这是在标量玩具模型的背景下进行的,其微扰波函数具有宇宙学多面体的第一性原理定义。特别是,我们使用的事实,即散射振幅编码在宇宙多面体的散射小平面,和削减的振幅编码在余维1边界的这方面。正如我们所示,平面空间的斯坦曼关系,从而暗示了不存在余维2边界的交叉点的边界与对部分重叠的通道。应用相同的参数,以充分的宇宙学多面体,我们也得到斯坦曼型约束,适用于全波函数的宇宙。这些论点显示了宇宙学多面体的组合性质如何导致S-矩阵中平坦空间因果关系的出现,并为宇宙波函数的分析结构提供了新的见解。

英文摘要:

The physical principles of causality and unitarity put strong constraints on the analytic structure of the flat-space S-matrix. In particular, these principles give rise to the Steinmann relations, which require that the double discontinuities of scattering amplitudes in partially-overlapping momentum channels vanish. Conversely, at cosmological scales, the imprint of causality and unitarity is in general less well understood---the wavefunction of the universe lives on the future space-like boundary, and has all time evolution integrated out. In the present work, we show how the flat-space Steinmann relations emerge from the structure of the wavefunction of the universe, and derive similar relations that apply to the wavefunction itself. This is done within the context of scalar toy models whose perturbative wavefunction has a first-principles definition in terms of cosmological polytopes. In particular, we use the fact that the scattering amplitude is encoded in the scattering facet of cosmological polytopes, and that cuts of the amplitude are encoded in the codimension-one boundaries of this facet. As we show, the flat-space Steinmann relations are thus implied by the non-existence of codimension-two boundaries at the intersection of the boundaries associated with pairs of partially-overlapping channels. Applying the same argument to the full cosmological polytope, we also derive Steinmann-type constraints that apply to the full wavefunction of the universe. These arguments show how the combinatorial properties of cosmological polytopes lead to the emergence of flat-space causality in the S-matrix, and provide new insights into the analytic structure of the wavefunction of the universe.

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。

↑