Revisiting slow-roll dynamics and the tensor tilt in general single-field inflation
Revisiting slow-roll dynamics and the tensor tilt in general single-field inflation
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DOI：
10.1103/physrevd.101.043536
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发表时间：
2019-11
影响因子：
5
通讯作者：
Y. Mishima;Tsutomu Kobayashi
中科院分区：
文献类型：
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作者：
Y. Mishima;Tsutomu Kobayashi
我们探索了 Horndeski 理论中势驱动的慢滚膨胀产生蓝色倾斜引力波谱的可能性。在 Kamada 等人中。 [物理。 Rev. D 86, 023504 (2012)PRVDAQ1550-799810.1103/PhysRevD.86.023504]，声称在 Horndeski 框架内无法从稳定的势驱动慢滚膨胀中获得蓝色引力波谱。然而，已经证明，在高斯-邦尼项的暴胀中，原初引力波的频谱可以是蓝色的，其中势项占主导地位，并且满足慢滚条件和稳定性条件。为了填补这一空白，我们澄清差异的来源。我们扩展了 Kamada 等人的表述。并表明，如果放宽先前施加在拉格朗日函数形式上的一些条件，则稳定的慢滚膨胀肯定可以产生蓝色引力波谱。
We explore the possibility of a blue-tilted gravitational wave spectrum from potential-driven slow-roll inflation in the Horndeski theory. In Kamada et al. [Phys. Rev. D 86, 023504 (2012)PRVDAQ1550-799810.1103/PhysRevD.86.023504], it was claimed that a blue gravitational wave spectrum cannot be obtained from stable potential-driven slow-roll inflation within the Horndeski framework. However, it has been demonstrated that the spectrum of primordial gravitational waves can be blue in inflation with the Gauss-Bonnet term, where the potential term is dominant and slow-roll conditions as well as the stability conditions are satisfied. To fill in this gap, we clarify where the discrepancy is coming from. We extend the formulation of Kamada et al. and show that a blue gravitational wave spectrum can certainly be generated from stable slow-roll inflation if some of the conditions previously imposed on the form of the free functions in the Lagrangian are relaxed.