标题： 从具有阶梯的混沌势能中的膨胀 显示英文标题

标题： Inflation from a chaotic potential with a step

摘要： 在本工作中，我们研究了来自具有阶梯的混沌势的暴胀宇宙对相关观测参数的影响。我们在冷暴胀和暖暴胀中数值演化扰动方程。一方面，在冷暴胀情景中，我们根据e-折叠数$N_{e}$分析标量功率谱$P_{\mathcal{R}}$，并根据比值$k/k_{0}$分析，其中$k_{0}$是我们的参考尺度。我们展示了$P_{\mathcal{R}}$如何围绕$0.2< k/k_{0} < 20$振荡。 此外，我们展示了两个相关参数的演化：标量谱指数$n_{s}$和张量-标量比$r$。 实际上，超过一个区域的$(n_{s},r)$位于可观测窗口内（Planck 2018）。 另一方面，在温暖暴胀的情况下，我们给出了两个例子，这两个例子都与之前的样本有关。 我们研究了标量功率谱随$N_{e}$的演化，可以观察到其振幅相对于更大的$k/k_{0}$有所增长。 这一结果可能意味着温暖阶跃势增强了$P_{\mathcal{R}}$在更大涨落尺度上的演化。 最后，这项研究的一个关键方面是对比两种范式中暴胀势的特征；事实上，它们在各种情况下表现出相似性和差异性。 在两种情景中一个显著的结果是，某些涨落尺度不再在超视界尺度上“冻结”。 因此，这一结果可能表明，在阶跃发生时纯粹的绝热原初密度扰动不再成立。 尽管如此，需要更深入的研究来确认超视界尺度上确实发生了熵产生。 另一方面，温暖暴胀可能作为一种屏蔽机制，能够平滑暴胀势的特征。 显示英文摘要

摘要： In this work we study the effects on relevant observational parameters of an inflationary universe from a chaotic potential with a step. We evolve numerically the perturbation equations within both cold and warm inflation. On the one hand, in a cold inflation scenario we analyse the scalar power spectrum $P_{\mathcal{R}}$ in terms of the number of e-folds $N_{e}$, and in terms of the ratio $k/k_{0}$, where $k_{0}$ is our pivot scale. We show how $P_{\mathcal{R}}$ oscillates around $0.2< k/k_{0} < 20$. Also, we present the evolution of two relevant parameters: the scalar spectral index $n_{s}$ and the tensor-to-scalar ratio $r$. Actually, more than one region of $(n_{s},r)$ lies within the observable window (Planck 2018). On the other hand, in the warm inflationary instance we present two examples, both related to previous samples. We examine the evolution of the scalar power spectrum in terms of $N_{e}$, where it can be observed a growth of its amplitude with respect to bigger $k/k_{0}$. This result might imply that a warm step potential enhances the evolution of $P_{\mathcal{R}}$ at larger fluctuation scales. Finally, one key aspect of this research was to contrast the features of an inflationary potential between both paradigms; and in fact they show similarities and differences among various cases. One remarkable upshot in both scenarios is that certain fluctuation scales are not longer "freeze in" on super-horizon scales. Thus, this outcome might suggest that purely adiabatic primordial density perturbations no longer holds at the time of the step. Nonetheless, a deeper study is needed to assure that entropy production is indeed happening at super-horizon scales. And on the other hand, warm inflation could function as a screening mechanism capable of smoothing the feature of the inflationary potential.