arXiv 1908.097972019-08hep-thastro-ph.COgr-qc

胖胀、大转弯和$η$问题

Fat Inflatons, Large Turns and the $η$-problem

Dibya Chakraborty, Roberta Chiovoloni, Oscar Loaiza-Brito, Gustavo Niz, Ivonne Zavala

备注：: 41 pages, 13 figures. Minor typos fixed, references added, appendix A expanded. To appear in JCAP
DOI：: 10.1088/1475-7516/2020/01/020

摘要：

通常认为，由单个或多个标量场驱动的暴胀的成功周期需要由$M_{inf}\ll H \ll M_{heavy}$给出的特定质量等级，其中$M_{inf}$可以对应于多个或单个光场，而$M_{heavy}\,\,\,$对应于任何重场，如果它满足适当的条件，则可以将其积分出来。这是暴胀中所谓的$η$问题的核心，因为对暴胀子质量的巨大贡献可能会破坏暴胀所需的慢滚条件。我们表明，虽然这是一个不可避免的结论，在单场暴胀，在多场暴胀，重领域如上所述，可能是完全负责一个成功的时期，我们称之为脂肪慢卷暴胀。此外，我们表明，在这种情况下，通货膨胀的轨迹，$Ω/H$的转折率，大于1。因此，$η$ -问题通过脂肪膨胀的大转弯来回避。根据微扰的质量谱，宇宙学的预言将与单场情形的预言略有不同或有很大不同。我们说明了这种情况下，在一个具体的例子中，在IIB型弦通量紧致化，其中探头D5膜移动沿角度和径向方向在一个扭曲的喉咙驱动脂肪D5膜自然膨胀。瞬时超普朗克衰变常数可以被定义，与我们的低能量近似一致，这要归功于几何的强烈翘曲。我们计算的宇宙学观测值，这不同于单场的情况。我们还讨论了脂肪通货膨胀的背景下，最近提出的沼泽地德Sitter地图。

英文摘要：

It is commonly believed that a successful period of inflation driven by a single or several scalar fields requires a specific hierarchy of masses given by $M_{inf}\ll H \ll M_{heavy}$, where $M_{inf}$ can correspond to several or a single light field and $M_{heavy}\,\,\,$ corresponds to any heavy field that might be integrated out if it satisfies suitable conditions. This is at the heart of the so called $η$-problem in inflation, since large contributions to the masses of the inflatons might spoil the slow-roll conditions required for inflation. We show that, while this is an unavoidable conclusion in single field inflation, in multifield inflation, heavy fields as defined above, may be fully responsible for a successful period of what we call fat slow-roll inflation. Moreover we show that in this scenario, the turning rate of the inflationary trajectory, $Ω/H$, is larger than one. Thus, the $η$-problem is evaded with large turns in fat inflation. Depending on the perturbations' mass spectra, cosmological predictions will differ either slightly or largely with respect to those of the single field case. We illustrate this scenario in a concrete example in Type IIB string flux compactifications, where a probe D5-brane moving along the angular and radial directions in a warped throat drives fat D5-brane natural inflation. An instantaneous superplanckian decay constant can be defined, consistent with our low energy approximations, thanks to the strong warping of the geometry. We compute the cosmological observables, which differ from the single field case. We also discuss fat inflation in the context of recently proposed swampland de Sitter conjectures.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

摘要：

英文摘要：

相关论文