发表机构
National Institute of Technology, Rourkela; Goethe Universität（鲁尔克拉国家理工学院; 歌德大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
研究引力耦合暗物质中子星的g模与f模，发现g模主要受对称能影响而非暗物质，暗核心对f模与潮汐形变率关系有微小但显著的偏离。
AI 中文摘要
成分引力（$g$）模已被提出作为探测中子星中暗物质的手段，其基础是暗物质与中子处于化学平衡的单流体模型。我们在完全广义相对论框架下计算了费米子暗物质仅通过引力与核子耦合的恒星的 $g$ 模和 $f$ 模，并利用 NICER 和 GW170817 数据推断暗物质质量分数，先验包含来自 Skyrme 和相对论平均场泛函的 $63$ 个核子状态方程（EOS），其中包括 Dutra 等人以及 Sun、Bhattiprolu 和 Lattimer 汇编的模型。数据不偏好暗物质，并给出其质量分数上限为 $0.12$--$0.26$（$95\%$），对应粒子质量为 $0.5$--$2$~GeV。仅通过引力耦合时，暗物质仅能通过引力场达到恢复 $g$ 模所需的浮力：一个含有 $10\%$ 质量的暗核心在固定 EOS 下将基态 $g$ 模频率提高 $10$--$15\%$，比单流体图像中的效应小数倍。更大的效应是间接的：具有暗核心的恒星需要更硬的核子 EOS，而由于 $g$ 模由对称能的密度依赖性决定，其频率反映的是恒星所需的 EOS，而非其包含的暗物质；在固定半径和对称能下，含有 $10\%$ 质量的暗核心等效于斜率 $L$ 变化 $9$--$12$~MeV。$f$ 模遵循平均密度，其行为不同：暗核心使 $f$ 模与潮汐形变率之间的关系偏离约百分之一，远超出核子恒星的后验分布范围。
英文摘要
Composition gravity ($g$) modes have been proposed as a probe of dark matter in neutron stars, on the basis of one-fluid models in which the dark matter is in chemical equilibrium with the neutrons. We computed in full general relativity the $g$- and $f$-modes of stars in which fermionic dark matter couples to the nucleons only through gravity, and inferred the dark mass fraction from NICER and GW170817 data with a prior that comprises $63$ nucleonic equations of state (EOSs) from Skyrme and relativistic mean-field functionals, among them the models of Dutra \textit{et al.} and of the compilation of Sun, Bhattiprolu and Lattimer. The data do not prefer dark matter and bound its mass fraction at $0.12 - 0.26$ ($95\%$) for particle masses of $0.5$--$2$~GeV. Coupled only through gravity, the dark matter reaches the buoyancy that restores a $g$-mode only through the gravitational field: a dark core holding $10\%$ of the mass raises the fundamental $g$-mode by $10-15\%$ at fixed EOS, several times less than in the one-fluid picture. The larger effect is indirect: a star with a dark core needs a stiffer nucleonic EOS, and since the $g$-mode is set by the density dependence of the symmetry energy, its frequency reflects the EOS that the star requires rather than the dark matter it contains; at fixed radius and symmetry energy a core holding $10\%$ of the mass is equivalent to a change of the slope $L$ of $9-12$~MeV. The $f$-mode, which follows the mean density, behaves differently: a dark core breaks the relation between the $f$-mode and the tidal deformability by about one percent, far outside the posterior spread of nucleonic stars.
Comments5 figures. Comments welcome
