Revisiting isocurvature bounds in models unifying the axion with the inflaton
Revisiting isocurvature bounds in models unifying the axion with the inflaton
复制标题
重新审视轴子与暴胀统一模型中的等曲率边界
DOI：
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发表时间：
2021
影响因子：
6.4
通讯作者：
Y. Welling
中科院分区：
文献类型：
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作者：
G. Ballesteros;A. Ringwald;C. Tamarit;Y. Welling
在膨胀之前或膨胀期间发生Peccei-Quinn对称性自发破缺的轴子场景，以及轴子暗物质产生于未对准机制的轴子场景，可以受到宇宙微波背景等曲率边界的约束。暗物质等曲率被认为是抑制模型与轴子暴胀相互作用，其中轴子扰动被假定为冻结在视界穿越暴胀期间。然而，由于相互作用本身，这种假设可能过于简单化。特别是，在再加热过程中的非微扰效应可能会导致轴子微扰的急剧增长。我们在两个模型中进行晶格计算，其中Peccei-Quinn场参与通货膨胀。我们发现，轴子扰动的增长是这样的，Peccei-Quinn对称性恢复的轴子衰变常数f A <$1016 -1017 GeV，导致暗物质的过剩，除非f A <$2 × 1011 GeV。对于f A ~ 1016-1017 GeV，我们仍然发现在低动量下轴子扰动的大量增长，这样一个天真的外推到CMB尺度表明违反了等曲率界限。
Axion scenarios in which the spontaneous breaking of the Peccei-Quinn symmetry takes place before or during inflation, and in which axion dark matter arises from the misalignment mechanism, can be constrained by Cosmic Microwave Background isocurvature bounds. Dark matter isocurvature is thought to be suppressed in models with axion-inflaton interactions, for which axion perturbations are assumed to freeze at horizon crossing during inflation. However, this assumption can be an oversimplification due to the interactions themselves. In particular, non-perturbative effects during reheating may lead to a dramatic growth of axion perturbations. We perform lattice calculations in two models in which the Peccei-Quinn field participates in inflation. We find that the growth of axion perturbations is such that the Peccei-Quinn symmetry is restored for an axion decay constant f A ≲ 1016–1017 GeV, leading to an over-abundance of dark matter, unless f A ≲ 2 × 1011 GeV. For f A ≳ 1016–1017 GeV we still find a large growth of axion perturbations at low momentum, such that a naive extrapolation to CMB scales suggests a violation of the isocurvature bounds.
影响因子：
19.6
作者：
Anastassopoulos, V.;Aune, S.;Zioutas, K.
通讯作者：
Zioutas, K.
影响因子：
12.5
作者：
Budker, Dmitry;Graham, Peter W.;Sushkov, Alexander O.
通讯作者：
Sushkov, Alexander O.
影响因子：
64.8
作者：
Borsanyi, S.;Fodor, Z.;Szabo, K. K.
通讯作者：
Szabo, K. K.