标题： 宇宙学中的早期再电离 显示英文标题

标题： Early Reionization in Cosmology

摘要： 宇宙微波背景（CMB）各向异性最终成为大尺度结构形成情景中最严格的“瓶颈”之一。 为了放松这一约束，有人提出早期再电离可以通过光子在电离等离子体中的扩散来阻尼CMB涨落的小尺度部分。 作为一个例子，我研究了最近提出的冷暗物质（CDM）和纹理种子的场景。 在那里，对CMB各向异性的分析表明，早期再电离是该场景的关键成分。 如果没有阻尼，小尺度各向异性将占据主导地位并超过观测限制。 本文中，我提出了由于塌缩纹理引起的CMB扰动而产生的由早期再电离导致的阻尼量的解析和数值结果。 此外，还计算了由于较热等离子体电子的康普顿散射造成的CMB谱畸变。 接下来，我讨论了导致电离程度、电子温度以及电离辐射演化之间的耦合常微分方程组的物理过程。 显示英文摘要

摘要： The cosmic microwave background (CMB) anisotropies have turned out to represent one of the most stringent 'bottle necks' for scenarios of large scale structure formation. As a possibility to relax this constraint, it has been proposed that early reionization can damp CMB fluctuations on small scales due to photon diffusion in the ionized plasma. As an example, I investigate the recently proposed scenario with cold dark matter (CDM) and texture seeds. There, an analysis of CMB anisotropies shows that early reionization is a crucial ingredient for this scenario. Without damping, the small scale anisotropies would dominate and exceed observed limits. In this paper I present analytical and numerical results for the amount of damping due to early reionization for CMB perturbations induced by a collapsing texture. Furthermore, the spectral distortion of the CMB due to Compton scattering of the hotter plasma electrons is calculated. Next I discuss the physical processes which lead to a system of coupled ordinary differential equations for the degree of ionization, the electron temperature and the evolution of the ionizing radiation.