EPRL/FK asymptotics and the flatness problem
EPRL/FK asymptotics and the flatness problem
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EPRL/FK 渐进和平坦度问题
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
J. Oliveira
中科院分区：
文献类型：
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作者：
J. Oliveira
自旋泡沫模型是一种基于态求和概念的量子引力方法，其目的是以一种其母体框架环量子引力尚未成功的方式来描述量子时空动力学。由于这些模型与经典爱因斯坦引力的关系并不明确，因此检验它们的可行性的一个重要方法是研究渐近性--经典理论应该在量子效应可以忽略的极限中得到，即在有边界的三角形流形上的大三角形区域的极限。本文简要介绍了EPRL/FK自旋泡沫模型及其渐近性的已知结果，然后描述了一个自旋泡沫的实际计算和一个只有一个内三角形的简单三角剖分的半经典几何数据。结果被用来评论的“平坦性问题”-Bonzom（2009年物理修订D 80 064028）提出的假设，这表明EPRL/FK的经典极限只描述了在真空中的平面几何形状。
Spin foam models are an approach to quantum gravity based on the concept of sum over states, which aims to describe quantum spacetime dynamics in a way that its parent framework, loop quantum gravity, has not as of yet succeeded. Since these models’ relation to classical Einstein gravity is not explicit, an important test of their viabilitiy is the study of asymptotics—the classical theory should be obtained in a limit where quantum effects are negligible, taken to be the limit of large triangle areas in a triangulated manifold with boundary. In this paper we will briefly introduce the EPRL/FK spin foam model and known results about its asymptotics, proceeding then to describe a practical computation of spin foam and semiclassical geometric data for a simple triangulation with only one interior triangle. The results are used to comment on the ‘flatness problem’—a hypothesis raised by Bonzom (2009 Phys. Rev. D 80 064028) suggesting that EPRL/FK’s classical limit only describes flat geometries in vacuum.
影响因子：
3.5
作者：
J. Barrett;R. J. Dowdall;W. Fairbairn;F. Hellmann;R. Pereira
通讯作者：
J. Barrett;R. J. Dowdall;W. Fairbairn;F. Hellmann;R. Pereira