标题： 暗物质来自高维原始黑洞 显示英文标题

标题： Dark Matter from Higher Dimensional Primordial Black Holes

摘要： 原始黑洞的蒸发提供了一种有前景的暗物质产生机制，且无需依赖暗物质与标准模型之间任何非引力相互作用。 在“大”额外维度（LEDs）理论中，量子引力的真实尺度$M_*$可能远低于普朗克尺度，从而允许高能粒子碰撞在早期宇宙的等离子体中以低至$T \gtrsim 100$GeV 的温度产生微观黑洞。此外，LEDs 修改了黑洞质量、半径和温度之间的关系，使得微观黑洞能够在早期宇宙中增长到宏观尺寸。 在这项工作中，我们研究了通过LED黑洞产生暗物质的三种情景：1）延迟蒸发黑洞（DEBHs），它们在最终蒸发之前增长到宏观尺寸；2）立即蒸发黑洞（IEBHs），它们立刻蒸发；3）质量为$M_*$的稳定黑洞遗迹，称为Planckeons。 对于给定的再加热温度$T_\mathrm{RH}$，我们表明 DEBHs 产生的暗物质显著少于 IEBHs 和 Planckeons。只要再加热尺度在范围$10^{-2} \leq T_\mathrm{RH}/M_* \leq 10^{-1}$内，IEBHs 就能够产生观测到的暗物质遗留丰度。我们计算了由此产生的暗物质的平均速度，并表明它对所有暗物质质量$m_{dm} \gtrsim 10^{-4}$GeV 都足够冷。 对于量子引力的任何尺度$10^4\,\mathrm{ GeV} \leq M_* \leq M_{Pl}$和任意数量的LEDs，此机制都是可行的。 显示英文摘要

摘要： The evaporation of primordial black holes provides a promising dark matter production mechanism without relying on any non-gravitational interactions between the dark sector and the Standard Model. In theories of ``Large'' Extra Dimensions (LEDs), the true scale of quantum gravity, $M_*$, could be well below the Planck scale, thus allowing for energetic particle collisions to produce microscopic black holes in the primordial plasma at temperatures as low as $T \gtrsim 100$ GeV. Additionally, LEDs modify the relationship between black hole mass, radius, and temperature, allowing microscopic black holes to grow to macroscopic sizes in the early Universe. In this work we study three scenarios for the production of dark matter via LED black holes: 1) Delayed Evaporating Black Holes (DEBHs) which grow to macroscopic sizes before ultimately evaporating, 2) Instantly Evaporating Black Holes (IEBHs) which immediately evaporate, and 3) stable black hole relics with a mass $M_*$ known as Planckeons. For a given reheating temperature, $T_\mathrm{RH}$, we show that DEBHs produce significantly less dark matter than both IEBHs and Planckeons. IEBHs are able to produce the observed relic abundance of dark matter so long as the reheating scale is in the range $10^{-2} \leq T_\mathrm{RH}/M_* \leq 10^{-1}$. We calculate the average speed for the resulting dark matter and show that it would be sufficiently cold for all dark matter masses $m_{dm} \gtrsim 10^{-4}$ GeV. This mechanism is viable for any scale of quantum gravity in the range $10^4\,\mathrm{ GeV} \leq M_* \leq M_{Pl}$ and for any number of LEDs.