Subleading effects and the field range in axion inflation
Subleading effects and the field range in axion inflation
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DOI：
10.1088/1475-7516/2016/04/008
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发表时间：
2016-02
影响因子：
6.4
通讯作者：
S. Parameswaran;G. Tasinato;I. Zavala
中科院分区：
文献类型：
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作者：
S. Parameswaran;G. Tasinato;I. Zavala
暴胀子的一个有吸引力的候选者是一个轴子，它在受微扰移位对称性保护的平坦势场中缓慢地滚下。在大场、自然暴胀和单项暴胀中实现这一思想，观测并不赞成，也很难嵌入弦理论。我们表明，subleading，但显着的非微扰修正可以将陡峭的悬崖和平缓的高原纳入潜在的，其总体效果是提高膨胀的e倍的数量。因此，与没有这种校正的电势相比，对于较小的场范围实现了足够的e折叠。因此，像弦论这样的UV完备理论中的单场自然暴胀和单项式暴胀，都可以用独特的特征恢复到对当前观测有利的状态。张量模式的结果小得难以观察，但谱指数有很大的负向变化。值得注意的是，自然暴胀可以用一个轴子衰变常数是次普朗克的单一场来实现。
An attractive candidate for the inflaton is an axion slowly rolling down a flat potential protected by a perturbative shift symmetry. Realisations of this idea within large field, natural and monomial inflation have been disfavoured by observations and are difficult to embed in string theory. We show that subleading, but significant non-perturbative corrections can superimpose sharp cliffs and gentle plateaus into the potential, whose overall effect is to enhance the number of e-folds of inflation. Sufficient e-folds are therefore achieved for smaller field ranges compared to the potential without such corrections. Thus, both single-field natural and monomial inflation in UV complete theories like string theory, can be restored into the favour of current observations, with distinctive signatures. Tensor modes result un-observably small, but there is a large negative running of the spectral index. Remarkably, natural inflation can be achieved with a single field whose axion decay constant is sub-Planckian.