On the validity of the perturbative description of axions during inflation
On the validity of the perturbative description of axions during inflation
复制标题
论暴胀过程中轴子微扰描述的有效性
DOI：
10.1088/1475-7516/2016/04/039
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发表时间：
2015
影响因子：
6.4
通讯作者：
M. Sloth
中科院分区：
文献类型：
--
作者：
Ricardo Z. Ferreira;Jonathan Ganc;Jorge Noreña;M. Sloth
轴子在大膨胀场模型的许多实现中以及最近在小场模型中产生原始张量模式的替代机制中发挥着核心作用。如果这些轴子耦合到规范场，耦合会产生一个快子不稳定性，导致规范场的指数增强，这反过来又会衰减成可观测的标量或张量曲率扰动。因此，一个完全自洽的治疗过程中的轴子通货膨胀是很重要的，在这项工作中，我们讨论了耦合到规范场的轴子的微扰约束。我们展示了如何通过这些替代机制产生张量模式最近的建议是在紧张与微扰理论中的形式主义。有趣的是，我们指出，约束参数弱于一个将估计的基础上天真的功率计数的规范场的传播。在非阿贝尔规范场的情况下，我们推导出新的约束的规范耦合的大小，这也适用于某些模型的自然大字段膨胀，如对齐机制。
Axions play a central role in many realizations of large field models of inflation and in recent alternative mechanisms for generating primordial tensor modes in small field models. If these axions couple to gauge fields, the coupling produces a tachyonic instability that leads to an exponential enhancement of the gauge fields, which in turn can decay into observable scalar or tensor curvature perturbations. Thus, a fully self-consistent treatment of axions during inflation is important, and in this work we discuss the perturbative constraints on axions coupled to gauge fields. We show how the recent proposal of generating tensor modes through these alternative mechanisms is in tension with perturbation theory in the in-in formalism. Interestingly, we point out that the constraints are parametrically weaker than one would estimate based on naive power counting of propagators of the gauge field. In the case of non-Abelian gauge fields, we derive new constraints on the size of the gauge coupling, which apply also in certain models of natural large field inflation, such as alignment mechanisms.
影响因子：
8.6
作者：
Ade, P. A. R.;Aikin, R. W.;Yoon, K. W.
通讯作者：
Yoon, K. W.