标题： 从弦理论通过6D超引力得到4D德西特空间 显示英文标题

标题： 4D de Sitter from String Theory via 6D Supergravity

摘要： 我们从受控的弦理论构造中获得德西特（dS）解。 我们回顾了最小规范手征6D超引力如何通过具有正标量势而避开标准的dS无定理，并描述已知的4D经典dS、AdS和闵可夫斯基解。 Grimm及其合作者最近通过直接的F理论卡拉比-丘流形通量紧化找到了相关的6D超引力，我们为此6D超引力构建了经典的4D最大对称解。 这些解提供了对应于4D中dS、AdS和平直时空的高维场方程的显式解，允许有趣的尺度层次结构。 我们展示了这些解的奇异性如何与额外维中两个充满空间的4D膜状源的反作用相一致，并利用点粒子有效场论（PPEFT）的形式推导出这些源的一些性质，表明这些源不是像D膜那样的普通对象。 这些工具将体场在近源区域的渐进行为与源的性质联系起来，并已在涉及小源反作用的更普通的物理系统中得到广泛验证，例如原子能级对核性质的依赖性。 我们用它来确定膜状源的张力（可以是正的）及其导数。 我们验证了这些解处于需要忽略量子和$\alpha'$效应的弱耦合/大体积区域。 显示英文摘要

摘要： We obtain de Sitter (dS) solutions from controlled string-theory constructions. We review how minimal gauged chiral 6D supergravity evades standard dS no-go theorems by having a positive scalar potential and describe the known 4D classical dS, AdS and Minkowski solutions. Grimm and collaborators recently found a related 6D supergravity by direct F-theory Calabi-Yau flux compactifications and we construct classical 4D maximally symmetric solutions for this 6D supergravity. These provide explicit solutions of the higher-dimensional field equations corresponding to dS, AdS and flat spacetimes in 4D, allowing interesting hierarchies of scales. We show how the singularities of these solutions are consistent with the back-reaction of two space-filling 4D brane-like sources situated within the extra dimensions and infer some of the properties of these sources using the formalism of point particle effective field theory (PPEFT), showing the sources are not vanilla objects like D branes. These tools relate the near-source asymptotic forms of bulk fields to source properties and have been extensively tested for more prosaic physical systems involving the back-reaction of small sources, such as the dependence of atomic energy levels on nuclear properties. We use it to determine the tension of the brane-like sources (that can be positive) and its derivatives. We verify that the solutions are in the weak coupling/large volume regime required to neglect quantum and $\alpha'$ effects.