Generalised tensor fluctuations and inflation
Generalised tensor fluctuations and inflation
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DOI：
10.1088/1475-7516/2015/01/029
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发表时间：
2014-09
影响因子：
6.4
通讯作者：
Dario Cannone;G. Tasinato;D. Wands
中科院分区：
文献类型：
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作者：
Dario Cannone;G. Tasinato;D. Wands
使用一个有效的场论方法通货膨胀，我们研究新的性质的频谱膨胀张量波动，出现时，打破一些对称性或要求通常施加在动力学的扰动。在单钟暴胀期间，时间重新参数化不变性被依赖于时间的宇宙学背景打破。为了探索更一般的情况下，我们考虑的可能性，也打破了有效质量项或微分算子的度量波动的拉格朗日空间的超同态不变性。我们调查的宇宙学后果的空间超态性的破坏，集中在运营商的影响波动的功率谱。我们确定的运营商张量波动，可以提供一个蓝色的光谱，而不违反零能量条件，和运营商的标量波动，导致非保守的超视界尺度上的同动曲率扰动，即使在单时钟膨胀。在我们工作的最后一部分，我们还研究了包含两个以上空间导数的算子的后果，讨论了它们如何影响张量波动的声速，并表明它们可以模拟对称破缺算子的一些有趣的效应，即使在保持空间同形不变性的情况下。
Using an effective field theory approach to inflation, we examine novel properties of the spectrum of inflationary tensor fluctuations, that arise when breaking some of the symmetries or requirements usually imposed on the dynamics of perturbations. During single-clock inflation, time-reparameterization invariance is broken by a time-dependent cosmological background. In order to explore more general scenarios, we consider the possibility that spatial diffeomorphism invariance is also broken by effective mass terms or by derivative operators for the metric fluctuations in the Lagrangian. We investigate the cosmological consequences of the breaking of spatial diffeomorphisms, focussing on operators that affect the power spectrum of fluctuations. We identify the operators for tensor fluctuations that can provide a blue spectrum without violating the null energy condition, and operators for scalar fluctuations that lead to non-conservation of the comoving curvature perturbation on superhorizon scales even in single-clock inflation. In the last part of our work, we also examine the consequences of operators containing more than two spatial derivatives, discussing how they affect the sound speed of tensor fluctuations, and showing that they can mimic some of the interesting effects of symmetry breaking operators, even in scenarios that preserve spatial diffeomorphism invariance.