暗物质输运抹除过冷相变产生的重子不均匀性
Dark Transport Erases Baryon Inhomogeneity from Supercooled Phase Transitions
- Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS)（基础科学研究院宇宙理论中心）
- Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences (HIAS-UCAS)（中国科学院大学杭州高等研究院）
- International Centre for Theoretical Physics Asia-Pacific (ICTP-AP)（亚太理论物理国际中心）
- Research Center for the Early Universe, The University of Tokyo（东京大学早期宇宙研究中心）
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交通大学李政道研究所）
- School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文提出暗物质产生场景中暗部门粒子输运可有效抹除过冷相变产生的重子空间不均匀性，避免大爆炸核合成约束，并给出抹除条件及相互作用约束。
AI中文摘要：
过冷相变可以产生可观测的引力波，但其气泡动力学也可能在重子不对称性中留下大尺度的空间不均匀性。对于TeV能标以下的相变，普通重子扩散可能过于缓慢，无法在大爆炸核合成之前抹除此类不均匀性，从而可能导致来自观测到的轻元素丰度的严格约束。我们表明，这一问题在暗物质产生（darkogenesis）场景中可以自然避免，在该场景中，相变首先在暗部门粒子中产生不对称性，随后该不对称性被转移至可见重子。暗部门粒子在衰变前可以传播比普通重子大得多的距离，从而在重子不对称性建立之前抹除不均匀性。我们推导了在扩散输运和无碰撞输运两种机制下有效抹除的条件，并将其转化为对暗部门相互作用的约束。对于一个代表性的暗相变，其再加热温度为$\mathcal{O}(1) \\,\mathrm{GeV}$，$β/H \simeq 10$，暗部门粒子寿命为$0.1\\,\mathrm{s}$，我们发现对于可行的相互作用范围，不均匀性可以被有效抹除。重要的是，相变前的重子生成既受到强过冷稀释的挑战，也受到随后空间不均匀性印记的挑战。这指向与相变相关的暗物质产生作为一个一致的框架，在该框架中，暗部门输运在将不均匀性转移至可见重子之前将其抹除。
英文摘要：
Supercooled phase transitions can generate observable gravitational waves, but their bubble dynamics may also imprint large spatial inhomogeneities in the baryon asymmetry. For phase transitions below the TeV scale, ordinary baryon diffusion can be too slow to erase such inhomogeneities before Big Bang Nucleosynthesis, potentially leading to stringent constraints from the observed light-element abundances. We show that this problem can be naturally avoided in darkogenesis scenarios, where the phase transition first generates an asymmetry in a dark-sector particle that is subsequently transferred to visible baryons. The dark-sector particle can travel over much larger distances than ordinary baryons before decaying, erasing the inhomogeneity before the baryon asymmetry is established. We derive the conditions for efficient erasure in both the diffusive and collisionless transport regimes and translate them into constraints on the dark-sector interactions. For a representative dark phase transition with a reheating temperature of $\mathcal{O}(1) \,\mathrm{GeV}$, $β/H \simeq 10$, and a dark-sector particle lifetime of $0.1\,\mathrm{s}$, we find that the inhomogeneity is efficiently erased for a viable range of the interactions. Importantly, baryogenesis before the phase transition is challenged both by dilution from strong supercooling and by the subsequent imprinting of spatial inhomogeneities. This points toward darkogenesis associated with the phase transition as a consistent framework, in which dark-sector transport erases the inhomogeneity before it is transferred to visible baryons.
