发表机构
Universitat de Barcelona; Institut de Ciències del Cosmos (ICCUB)（巴塞罗那大学; 宇宙科学研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究探讨原初夸克颗粒（PQP）能否解决暗物质难题。通过特定条件使其在辐射主导宇宙中自然出现，求解相关方程得出其特性，其形成概率可再现暗物质密度，质量低于一定值时能避开微透镜约束，或为暗物质难题提供基于标准模型且可观测检验的解决方案。
AI 中文摘要
我们表明，如果通过佩切伊 - 奎因域壁或类似超视界结构坍缩产生罕见的重子过密度，那么在辐射主导的宇宙中自然会出现原初夸克颗粒（PQP），即大约在1 TeV形成的超致密夸克物质微型恒星。用热夸克状态方程求解托尔曼 - 奥本海默 - 沃尔科夫方程，我们发现稳定解，最大质量为$10^{-2}$太阳质量，半径约100米，尽管形成机制倾向于更小的物体。一旦形成，PQP会冷却并根据量子色动力学基态演变成微型中子星或稳定的奇异物质块。每个视界体积$10^{-9}$到$10^{-4}$的形成概率足以再现当前暗物质密度，而无需改变大爆炸核合成或熵稀释。如果PQP质量低于$10^{-7}$太阳质量，它们可以完全避开微透镜约束，这个范围很容易容纳大部分暗物质。因此，PQP可能构成一个保守的、基于标准模型且可通过观测检验的暗物质难题解决方案。
英文摘要
We show that primordial quark pellets (PQPs) - ultra-dense quark-matter mini-stars formed at $T\sim 1$ GeV - could naturally arise in a radiation dominated early universe if rare baryon overdensities are produced by contracting Peccei-Quinn domain walls or similar super-horizon structures. Solving the Tolman-Oppenheimer-Volkoff equation with a hot quark equation of state, we find stable solutions with a maximum theoretical mass of $10^{-2}$ solar masses and radii of order 100 m, although the formation mechanism favours much lighter objects that would indeed be dominant. Once formed, PQPs cool and evolve into either mini neutron stars or stable strange-matter nuggets, depending on the QCD ground state. The mechanism we present could suffice to reproduce the present dark matter density without altering Big Bang Nucleosynthesis or requiring a posterior entropy injection. PQPs may evade current microlensing constraints if their masses are below $10^{-8}$ solar masses, a range that in view of their mass function could easily accommodate a large fraction of dark matter. PQPs thus potentially constitute a conservative Standars-Model based, and observationally testable candidate.
