论文标题
几乎热费米斯暗物质的重力产生
Gravitational production of nearly thermal fermionic Dark Matter
论文作者
论文摘要
我们考虑到通货膨胀期间费米文化暗物质的宇宙学生产和通货膨胀后的辐射主导。此费米昂\ emph {仅相互作用在重力}中，其质量$ m $比通货膨胀期间的哈勃尺度小得多（但其他是任意的），并且在通货膨胀期间处于其束davies真空状态。我们专注于通货膨胀结束时的超级罐模式，并假设瞬时加热。我们获得了讨论其重新归化的全能量动量张量，并表明粒子产生的贡献是物质辐射平等的动能形式。我们发现\ emph {}产生的粒子的分布函数$ | b（k）|^2 = \ frac {1} {2} {2} \ big [1-（1-e^{ - \ frac {k^2} {2mt_h}} {2mt_h}}}}}） $ t_h = h_0 \ sqrt {ω_r} \ simeq 10^{ - 36}（\ mathrm {ev}）$。产生的颗粒的丰度$ω_{pp} $与在温度下在温度下热授予非相关的自由度非常相似\ big（m/10^8 \ mathrm {gev}）\ big）^{5/2} $和状态$ w（a）\ simeq（t_h/m a^2）$的“冷”方程，两者在通货膨胀结束时由超级方模式统治。我们讨论了同化扰动的细微方面。
We consider the cosmological production of fermionic dark matter during inflation and a post-inflationary radiation dominated era. This fermion \emph{only interacts gravitationally}, has a mass $m$ much smaller than the Hubble scale during inflation (but is otherwise arbitrary) and is in its Bunch-Davies vacuum state during inflation. We focus on superhorizon modes at the end of inflation, and assume instantaneous reheating. We obtain the full energy momentum tensor discussing its renormalization, and show that the contribution from particle production is of the kinetic-fluid form near matter-radiation equality. We find \emph{exactly} the distribution function of produced particles $|B(k)|^2=\frac{1}{2}\Big[1-(1-e^{-\frac{k^2}{2mT_H}})^{1/2}\Big]$ which exhibits an " emergent temperature" $T_H=H_0\sqrt{Ω_R}\simeq 10^{-36}(\mathrm{eV})$. The abundance of the produced particles $Ω_{pp}$ is very similar to that of a non-relativistic degree of freedom thermalized at temperature $T_H$, $Ω_{pp} \propto m \, (m\,T_H)^{3/2}\simeq \big(m/10^8\mathrm{GeV})\big)^{5/2}$ and "cold" equation of state $w(a) \simeq (T_H/m a^2)$, both dominated by superhorizon modes at the end of inflation. We discuss subtle aspects of isocurvature perturbations.
