标题： 对称能对快速旋转中子星性质及普遍关系的影响 显示英文标题

标题： Effect of symmetry energy on properties of rapidly rotating neutron stars and universal relations

摘要： 我们研究了在开普勒（质量流失）极限下旋转的致密星体的普遍关系，这与理解中子星-中子星合并后形成的快速旋转天体密切相关。 我们的分析基于一组核物质状态方程，这些状态方程在对称能斜率参数$L_{\rm sym}$和标量偏度参数$Q_{\rm sat}$方面具有系统性变化，并且这些参数的变化范围大致符合当前实验室和天体物理约束。 研究了孤立的最大旋转星体的整体可观测特性，重点在于质量-半径关系、转动惯量、四极矩以及开普勒（最大）旋转频率，以及它们在$L_{\rm sym}$-$Q_{\rm sat}$参数空间中的变化。 接下来，我们证明了在开普勒旋转极限下，普遍关系仍然适用于由不同$L_{\rm sym}$和$Q_{\rm sat}$特征化的同一组状态方程。 特别是，我们给出了转动惯量和四极矩作为紧凑度的函数，以及转动惯量-四极矩关系的显式结果。 所有这些关系都表现出极好的普遍性，偏差通常在几个百分点以内，在广泛的参数范围内很少超过10%。 这些发现支持了$I$-Love-$Q$-型通用关系在考虑对称能量显著变化和核EoS高密度行为时，在最大旋转致密星及其发出的引力波的观测建模中的适用性。 显示英文摘要

摘要： We investigated universal relations for compact stars rotating at the Keplerian (mass-shedding) limit, which is highly relevant for understanding the rapidly rotating objects formed in the aftermath of a neutron star-neutron star merger. Our analysis is based on a set of nucleonic EoS featuring systematic variations in the symmetry energy slope parameter $L_{\rm sym}$ and the isoscalar skewness parameter $Q_{\rm sat}$, varied within ranges that are broadly consistent with current laboratory and astrophysical constraints. The global observable properties of isolated maximally rotating stars are examined, focusing on the mass-radius relation, moment of inertia, quadrupole moment, and the Keplerian (maximum) rotation frequency, as well as their variations in the $L_{\rm sym}$-$Q_{\rm sat}$ parameter space. Next, we demonstrate that, in the limit of Keplerian rotation, universal relations remain valid across the same set of EoSs characterized by varying $L_{\rm sym}$ and $Q_{\rm sat}$. In particular, we present explicit results for the moment of inertia and quadrupole moment as functions of compactness, as well as for the moment of inertia - quadrupole moment relation. All of these relations exhibit excellent universality, with deviations typically within a few percent and rarely exceeding 10\% across a wide range of parameters. These findings support the applicability of $I$-Love-$Q$-type universal relations in observational modeling of maximally rotating compact stars and the gravitational wave emitted by them, when accounting for significant variation in the symmetry energy and high-density behavior of the nuclear EoS.