标题： 弦 inflation 中的低-l CMB 功率损失 显示英文标题

标题： Low-l CMB Power Loss in String Inflation

摘要： 大尺度（l < 40）上功率缺乏的现象可能已被 PLANCK 卫星观测到。 我们认为这一假定的特征可以通过通胀初期的快速滚动阶段来解释。 我们表明，在单场模型的背景下，需要的是一个非对称拐点模型，纤维通胀是一个弦理论启发的例子。 我们研究了纤维通胀在生成低 l CMB 两点函数功率抑制的能力，发现由弦环导出的势能对于此目的不够陡峭。 我们引入了势能的一个更陡峭的贡献，该贡献在非通胀区域占主导，并证明如果适当调整，确实可以导致大尺度上功率缺乏的谱。 显示英文摘要

摘要： The lack of power on large scales (l < 40) might have been observed by the PLANCK satellite. We argue that this putative feature can be explained by a phase of fast roll at the onset of inflation. We show that in the context of single field models what is required is an asymmetric inflection point model of which fibre inflation is a string motivated example. We study the ability of fibre inflation to generate a suppression of the CMB 2-point function power at low l, finding that the potential derived from string loops is not steep enough for this purpose. We introduce a steeper contribution to the potential, that dominates away from the inflationary region, and show that if properly tuned it can indeed lead to a spectrum with lack of power at large scales.