发表机构
Institut d’Astrophysique de Paris; University of Louvain（巴黎天体物理研究所; 鲁汶大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出拐点暴胀中暴胀子仍经历有效超慢滚，spectator场仅抬升势能并解耦，模式混合仅缓和功率谱凹陷，为研究参数依赖提供简单方法。
AI 中文摘要
拐点暴胀的单场模型会经历一段超慢滚（USR）阶段，从而导致曲率扰动被放大。最近，Lorenzoni等人通过添加一个轻的 spectator 场修改了该场景，表明该场通过为第一慢滚参数 $\epsilon$ 设定一个下限而破坏了USR。与等曲率扰动的混合仍然会放大曲率功率谱。我们提出另一种观点，认为暴胀子仍然经历有效的USR。spectator 场以一个常数量抬升势能，暴胀子扰动在抬升后的拐点势中遵循单场动力学，并与 spectator 扰动解耦。模式混合仅影响功率谱的凹陷，使其变得更平缓。我们通过示例模型数值演示了这种有效的单场行为。我们的结果为研究模型的参数依赖性提供了一种简单的方法。
英文摘要
Single-field models of inflection point inflation experience a phase of ultra-slow roll (USR), leading to amplified curvature perturbations. Recently, Lorenzoni et al. modified the scenario by adding a light spectator field, showing that it ruins USR by setting a floor for the first slow-roll parameter $ε$. Mixing with isocurvature perturbations still amplifies the curvature power spectrum. We offer an alternative point of view, arguing that the inflaton still undergoes effective USR. The spectator lifts the potential by a constant amount, and the inflaton perturbations follow single-field dynamics in the lifted inflection point potential, decoupling from the spectator perturbations. Mode mixing only affects the power spectrum dip, making it milder. We demonstrate this effective single-field behavior numerically for example models. Our results offer a simple way to study the models' parameter dependence.
Comments11 pages, 5 figures, 3 appendices
