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arXiv 2204.08657astro-ph.CO
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热暴胀宇宙学扰动建模

Modeling Cosmological Perturbations of Thermal Inflation

Jeong-Myeong Bae, Sungwook E. Hong, Heeseung Zoe

备注：
22 pages, 6 figures, accepted to the Class. Quant. Grav
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AI总结：

本文用物质、辐射和真空组分模型研究热暴胀对原初扰动的放大作用，推导由参数 $\upsilon$ 及特征尺度控制的传递函数及其分区行为。

摘要：

我们考虑一个由物质、辐射和真空组分构成的简单系统，以模拟热暴胀对原初扰动演化的影响。真空能会放大在其主导之前进入视界的原初模式，使这些模式有可能被观测到，而由此产生的传递函数反映了相变和能量组分。为确定传递函数，我们追踪曲率扰动从辐射主导时期远在视界之外，到真空主导时期仍远在视界之外的过程，并在恒定辐射密度超曲面上对其进行评估，这正适合热暴胀情形。传递函数的形状由物质—辐射相等时真空能与辐射之比决定，我们将其记为 $\upsilon$，并有两个特征尺度 $k_{\rm a}$ 和 $k_{\rm b}$，分别对应物质—辐射相等时和暴胀开始时的视界大小。若 $\upsilon \ll 1$，宇宙经历辐射、物质和真空主导时代，传递函数在 $k \ll k_{\rm b}$ 时平坦，在 $k_{\rm b} \ll k \ll k_{\rm a}$ 时以振幅 $1/5$ 振荡，并在 $k \gg k_{\rm a}$ 时以振幅 $1$ 振荡。对于 $\upsilon \gg 1$，物质主导时代消失，传递函数简化为在 $k \ll k_{\rm b}$ 时平坦，并在 $k \gg k_{\rm b}$ 时以振幅 $1$ 振荡。

英文摘要：

We consider a simple system consisting of matter, radiation and vacuum components to model the impact of thermal inflation on the evolution of primordial perturbations. The vacuum energy magnifies the primordial modes entering the horizon before its domination, making them potentially observable, and the resulting transfer function reflects the phase changes and energy contents. To determine the transfer function, we follow the curvature perturbation from well outside the horizon during radiation domination to well outside the horizon during vacuum domination and evaluate it on a constant radiation density hypersurface, as is appropriate for the case of thermal inflation. The shape of the transfer function is determined by the ratio of vacuum energy to radiation at matter-radiation equality, which we denote by $\upsilon$, and has two characteristic scales, $k_{\rm a}$ and $k_{\rm b}$, corresponding to the horizon sizes at matter radiation equality and the beginning of the inflation, respectively. If $\upsilon \ll 1$, the universe experiences radiation, matter and vacuum domination eras and the transfer function is flat for $k \ll k_{\rm b}$, oscillates with amplitude $1/5$ for $ k_{\rm b} \ll k \ll k_{\rm a}$ and oscillates with amplitude $1$ for $k \gg k_{\rm a}$. For $\upsilon \gg 1$, the matter domination era disappears, and the transfer function reduces to being flat for $k \ll k_{\rm b}$ and oscillating with amplitude $1$ for $k \gg k_{\rm b}$.

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。

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