白矮星-中子星物质转变及轻元素的影响
White dwarf-neutron star matter transition and the effect of light elements
AI总结：
本文建立统一的相对论平均场框架，研究白矮星与中子星的物质转变，计算轻元素孕育的白矮星质量-半径关系，发现轻元素包层对中子星半径影响极小，该框架可用于相关多信使现象研究。
AI中文摘要：
白矮星和中子星是致密核物质物理的独特实验室。我们开发了一种单一的相对论平均场框架，该框架以同等基础处理两类致密星及其之间的转变：白矮星物质的原子核作为包含完整电磁相互作用的维格纳-塞茨胞自洽求解，而同一拉格朗日量则给出中子星内部的均匀核物质。在该统一描述中，我们计算由$^4$He、$^{12}$C和$^{16}$O孕育的轻元素白矮星，沿每条固定质量数$A$序列的中子化路径追踪，并通过精确的麦克斯韦结将其连接到中子星分支，由此推导对应的质量-半径关系。氦和碳孕育的白矮星序列分别达到约1.4倍太阳质量（$M_\bigodot$）和约1.0倍太阳质量的最大质量。在中子星分支，保留的轻元素包层仅在百分之一的水平改变预测半径——在1.4倍太阳质量时约改变0.2千米，处于当前观测不确定度范围内。该统一框架提供了从白矮星到中子星密度的一致零温物态方程，为白矮星-中子星双星并合、前身星演化、分赫兹引力波源及相关多信使现象的研究提供了自然起点。
英文摘要：
White dwarfs and neutron stars are unique laboratories for dense nuclear matter physics. We develop a single relativistic mean-field framework that treats both classes of compact star, and the transition between them, on the same footing: the nuclei of white-dwarf matter are solved self-consistently as Wigner-Seitz cells with the full electromagnetic interaction, while the same Lagrangian yields the uniform nuclear matter of the neutron-star interior. Within this unified description we compute light-element white dwarfs seeded by $^4$He, $^{12}$C, and $^{16}$O, following each fixed-$A$ sequence along its neutronization path and connecting it to the neutron-star branch through exact Maxwell junctions, from which the corresponding mass-radius relations are derived. The helium- and carbon-seeded white-dwarf sequences attain maximum masses of ${\sim}1.4\,M_\odot$ and ${\sim}1.0\,M_\odot$, respectively. On the neutron-star branch, the retained light-element envelope changes the predicted radii only at the percent level---by approximately $0.2~$km at $1.4\,M_\odot$, within current observational uncertainties. Providing a consistent zero-temperature equation of state from white-dwarf to neutron-star densities, this unified framework offers a natural starting point for studies of white-dwarf--neutron-star binary mergers, progenitor-star evolution, decihertz gravitational-wave sources, and related multimessenger phenomena.
