标题： 论暴胀扰动的尺度不变性程度 显示英文标题

标题： On the degree of scale invariance of inflationary perturbations

摘要： 许多，如果不是大多数，通胀模型预测密度扰动谱的幂律指数接近于一，但不完全等于一，|n-1| \sim O(0.1)，这意味着密度扰动谱几乎是尺度不变的，但并非完全不变。 一些模型允许n显著小于一（n \sim 0.7）；显著大于一的光谱指数更难实现。 我们证明n \approx 1是通胀的慢滚条件和“自然性”的结果，因此是通胀的普遍预测。 我们讨论偏离尺度不变性所需的条件，然后通过显式构造，展示满足成功通胀所有条件并给出 $n$ 大至2的平滑势能的存在。 显示英文摘要

摘要： Many, if not most, inflationary models predict the power-law index of the spectrum of density perturbations is close to one, though not precisely equal to one, |n-1| \sim O(0.1), implying that the spectrum of density perturbations is nearly, but not exactly, scale invariant. Some models allow n to be significantly less than one (n \sim 0.7); a spectral index significantly greater than one is more difficult to achieve. We show that n \approx 1 is a consequence of the slow-roll conditions for inflation and ``naturalness,'' and thus is a generic prediction of inflation. We discuss what is required to deviate significantly from scale invariance, and then show, by explicit construction, the existence of smooth potentials that satisfy all the conditions for successful inflation and give $n$ as large as 2.