Propagators for gauge-invariant observables in cosmology
Propagators for gauge-invariant observables in cosmology
复制标题
宇宙学中规范不变可观测量的传播器
DOI：
10.1088/1361-6382/aab427
复制
发表时间：
2017
影响因子：
3.5
通讯作者：
W. C. Lima
中科院分区：
文献类型：
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作者：
M. Fröb;W. C. Lima
基于 Brunetti 等人最近的工作 (2016 J. High Energy Phys. JHEP08(2016)032)，我们提出了宇宙时空微扰量子引力中规范不变可观测量的建议。这些可观测量是相关的，并且是通过在依赖于场的坐标系中评估场算子而获得的。我们证明，可以定义这个坐标系，使得量子引力中任何高阶可观测量固有的非局域性都是因果关系，即点 x 处的规范不变可观测量的值仅取决于 x 过去光锥中的度量和膨胀扰动。然后，我们在适应该坐标系的规范中构建度量和暴胀扰动的传播器，这简化了环路校正的计算，并给出了相关情况的明确表达式：物质和辐射主导的时代和慢滚暴胀。
We make a proposal for gauge-invariant observables in perturbative quantum gravity in cosmological spacetimes, building on the recent work of Brunetti et al (2016 J. High Energy Phys. JHEP08(2016)032). These observables are relational, and are obtained by evaluating the field operator in a field-dependent coordinate system. We show that it is possible to define this coordinate system such that the non-localities inherent in any higher-order observable in quantum gravity are causal, i.e. the value of the gauge-invariant observable at a point x only depends on the metric and inflation perturbations in the past light cone of x. We then construct propagators for the metric and inflaton perturbations in a gauge adapted to that coordinate system, which simplifies the calculation of loop corrections, and give explicit expressions for relevant cases: matter- and radiation-dominated eras and slow-roll inflation.
DOI：
10.4171/037
发表时间：
2007-03
期刊：
--
影响因子：
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作者：
Christian Baer;N. Ginoux;Frank Pfaeffle
通讯作者：
Christian Baer;N. Ginoux;Frank Pfaeffle