Constraining axion inflation with gravitational waves from preheating
Constraining axion inflation with gravitational waves from preheating
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DOI：
10.1103/physrevd.101.083534
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发表时间：
2020-04-27
影响因子：
5
通讯作者：
Weiner, Zachary J.
中科院分区：
文献类型：
--
作者：
Adshead, Peter;Giblin, John T., Jr.;Weiner, Zachary J.
我们在各种膨胀模型中研究了标尺预热产生的引力波，详细说明了引力波对能量尺度和势的形状的依赖关系。我们发现，预热到阿贝尔规范场通常会导致一个大的引力波背景，这对早期宇宙中的有效相对论自由度N-ef有很大的贡献。我们证明了引力波的产生效率与张量标量比r有关。特别是，我们证明了在新一代宇宙微波背景实验将探测到张量标量比(r大于或类似于10(-3))的模型中，有效的规范预热要么通过它对N-Eff的贡献被检测到，要么被排除在外。此外，我们还表明，无论位势如何，N-Eff的边界提供了最灵敏的探测，以探测膨胀子轴向耦合的可能情况。
We study gravitational wave production from gauge preheating in a variety of inflationary models, detailing its dependence on both the energy scale and the shape of the potential. We show that preheating into Abelian gauge fields generically leads to a large gravitational wave background that contributes significantly to the effective number of relativistic degrees of freedom in the early universe, N-eff. We demonstrate that the efficiency of gravitational wave production is correlated with the tensor-to-scalar ratio, r. In particular, we show that efficient gauge preheating in models whose tensor-to-scalar ratio would be detected by next-generation cosmic microwave background experiments (r greater than or similar to 10(-3)) will be either detected through its contribution to N-eff or ruled out. Furthermore, we show that bounds on N-eff provide the most sensitive probe of the possible axial coupling of the inflaton to gauge fields regardless of the potential.