论文标题
自然充气，与重力非最小的耦合
Natural inflation with a nonminimal coupling to gravity
论文作者
论文摘要
尽管自然通货膨胀是一种理论上动机的宇宙通胀模型，但它与最近的普朗克宇宙微波背景各向异性测量值保持紧张。我们提出了一种减轻这种张力的方法，通过考虑在两种情况下，在公制和帕拉蒂尼的一般相对性的公式中，充气场与重力的非微小耦合非常弱。我们以与RICCI标量的通用耦合的通用形式开始讨论，然后专注于一种简单的形式来进行现象学研究。我们的结果表明，这种扩展可以将自然通货膨胀的预测带入与普朗克数据达成良好同意。取决于耦合常数$ξ$和对称破坏量表$ f $的值，我们发现，$ |ξ| \ sim 10^{ - 3} $和$ f \ gtrsim 2.0 m _ {\ mathrm {pl Mathrm {pl}} $预测该模型的预测允许$ 68 \％$ f $ f $ f $ f $7。 M _ {\ Mathrm {pl}} $，然后在$ 95 \％$ cl区域内仅在$ f $之后超过后一个值。由于我们使用的耦合函数的简单形式以及耦合$ξ$的较小幅度，因此公制和Palatini理论的预测非常相似。成功的再加热也可以在此模型中实现。
Although natural inflation is a theoretically well-motivated model for cosmic inflation, it is in tension with recent Planck cosmic microwave background anisotropy measurements. We present a way to alleviate this tension by considering a very weak nonminimal coupling of the inflaton field to gravity in both contexts of metric and Palatini formulations of general relativity. We start our discussions with a generic form of the inflaton coupling to the Ricci scalar, then focus on a simple form to do phenomenological study. Our results show that such an extension can bring natural inflation's predictions to a good agreement with the Planck data. Depending on values of the coupling constant $ξ$ and the symmetry breaking scale $f$, we find that with $|ξ|\sim 10^{-3}$ and $f\gtrsim 2.0 M_{\mathrm{pl}}$ predictions of the model stay inside $68\%$ CL allowed region until $f$ increases up to $7.7 M_{\mathrm{pl}}$, then only inside $95\%$ CL region after $f$ exceeds the latter value. The predictions from the metric and the Palatini theories are very similar due to the simple form of the coupling function we use and the small magnitude of the coupling $ξ$. Successful reheating can also be realized in this model.
