Constructing Infrared Finite Propagators in Inflating Space-time
Constructing Infrared Finite Propagators in Inflating Space-time
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在膨胀时空中构建红外有限传播器
DOI：
10.1103/physrevd.82.023525
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
A. Rajaraman
中科院分区：
文献类型：
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作者：
J. Kumar;Louis Leblond;A. Rajaraman
通常的（Bunch-Davies）Feynman无质量场的传播子在膨胀宇宙中由于红外发散的存在而不能很好地定义。我们提出了一个新的传播，产生IR有限的答案，任何相关函数。关键是，在德西特时空中，传播子的零模存在模糊性。这种不确定性可以用来抵消在某些循环计算中出现的在永恒（或半永恒）膨胀时空中的明显发散。我们把这个过程称为零模修正。剩余模糊度由观测量确定。
The usual (Bunch-Davies) Feynman propagator of a massless field is not well defined in an expanding universe due to the presence of infrared divergences. We propose a new propagator which yields IR finite answers to any correlation function. The key point is that in a de Sitter space-time there is an ambiguity in the zero mode of the propagator. This ambiguity can be used to cancel the apparent divergences which arise in some loop calculations in eternally (or semieternally) inflating space-time. We refer to this process as zero-mode modification. The residual ambiguity is fixed by observational measurement.