Cosmology and Effective Field Theory in Warped Extra Dimension

在粒子理论和宇宙学的交叉点上存在着一些基本问题。为什么引力与其他基本力如此不同？为什么它如此脆弱（层次问题）？宇宙的暗能量是什么？是什么推动了暴胀，使宇宙变得平滑，同时播种结构的形成？弦论和M理论需要额外的空间维度：它们如何解释我们感知到的3D宇宙？最近对最后一个问题的研究，额外维度，照亮了所有其他的问题。在这个项目中，PI研究了一类额外维度模型：那些额外维度围绕3-膜扭曲或弯曲的模型？一个3D的子宇宙，里面有普通物质弦理论和M理论预言了这样的膜;由于广义相对论，它们会扭曲时空;它们的扭曲使引力和粒子相互作用有效地呈现为3D。PI的工作使用额外维度场论校准了扭曲粒子的相互作用。因此，膜世界从更高维度预测了一个明确的3D宇宙。此外，他们提供了一个动态的手段，减少维：相变扭曲一些领域在额外的维度，自发地限制重力和普通物质，由于一个巨大的3-膜形成在扭曲的缺陷？的核心。

At the intersection of particle theory and cosmology lie fundamental questions. Why is gravity so different from other fundamental forces? Why is it so weak (the hierarchy problem)? What is the universe's dark energy? What drives inflation, smoothing the universe while seeding structure formation? String and M theories require extra spatial dimensions: how could they explain our perceived 3D universe? Recent work on this last question, extra dimension, illuminates all the others. In this project, the PI investigates a class of extra dimensional models: those where extra dimensions warp, or curve, around a 3-brane ? a 3D sub-universe trapping ordinary matter. Such branes are predicted by string and M theory; they warp space-time, due to general relativity; and their warp renders both gravity and particle interactions effectively 3D. The PI's work calibrates the warped particle interactions, using extra-dimensional field theory. Braneworlds thus predict a well-specified 3D universe, from one of higher dimension. Furthermore, they provide a dynamic means of dimensional reduction: a phase transition twists some field in the extra dimensions, spontaneously confining both gravity and ordinary matter, due to a massive 3-brane formed at the twisting defect?s core.