希格斯门户费米子暗物质对中子星潮汐形变及质量-半径斜率的印记
Imprints of Higgs-portal fermionic dark matter on neutron-star tidal deformability and the mass-radius slope
浏览论文内容
中文总结 AI 辅助
研究混合费米子暗物质的中子星结构，用DDRMF泛函求解相关方程得到多项数据。发现DM使状态方程变软，降低相关物理量。通过分析潮汐形变和质量 - 半径斜率，表明\(\Lambda\)是敏锐判别器，可据此区分DM印记与核子不确定性。
中文摘要 AI 辅助
我们使用三种依赖密度的相对论平均场（DDRMF）泛函（DDME、DDB和GDFM）来研究混合了费米子暗物质（DM）的中子星（NSs）结构，用于β平衡核子物质。将DM建模为通过希格斯交换相互作用的最轻中性粒子，把DM费米动量\(k_F^{\rm DM}\)作为控制参数，范围在\(0.02 - 0.06\)GeV。通过求解耦合平均场和托尔曼 - 奥本海默 - 沃尔科夫方程来获得质量 - 半径关系、最大质量\(M_{\rm max}\)、径向声速剖面\(c_s^2\)和潮汐形变\(\Lambda\)。在所有模型中，随着\(k_F^{\rm DM}\)增加，DM使状态方程变软，系统地降低\(M_{\rm max}\)、\(1.4M_{\odot}\)时的半径\(R_{1.4}\)和\(1.4M_{\odot}\)时的潮汐形变\(\Lambda_{1.4}\)。因此，\(2M_\odot\)脉冲星极限和NICER数据对DM含量设置了模型依赖的上限，而GW170817潮汐约束对最硬泛函要求最小DM含量。利用最近对DDRMF状态方程的贝叶斯推断作为核子参考带，评估仅使用可测量量能否将这种DM印记与核子不确定性区分开。分析固定质量下的潮汐形变\(\Lambda\)和质量 - 半径斜率\(dR/dM\)，发现\(\Lambda\)是一个敏锐的判别器：在\(1.4M_{\odot}\)和\(k_F^{\rm DM}=0.06\)GeV时，DM引起的\(\Lambda\)减少达到核子\(1\sigma\)宽度的约8倍（与模型无关为\(7.5 - 7.8\sigma\)）。当\(k_F^{\rm DM}\gtrsim0.03 - 0.04\)GeV时，DM轨迹离开核子\(1\sigma\)带，而\(dR/dM\)仅对较重（\(1.8 - 2.0M_{\odot}\)）分支具有诊断性。
英文摘要
We investigate the structure of neutron stars (NSs) admixed with fermionic dark matter (DM) using three density-dependent relativistic mean-field (DDRMF) functionals (DDME, DDB, and GDFM) for $β$-equilibrated nucleonic matter. Modeling DM as the lightest neutralino interacting via Higgs exchange, we treat the DM Fermi momentum $k_F^{\rm DM}$ as a control parameter in the range $0.02$-$0.06$ GeV. We solve the coupled mean-field and Tolman-Oppenheimer-Volkoff equations to obtain the mass-radius relation, maximum mass $M_{\rm max}$, radial sound speed profile $c_s^2$, and tidal deformability $Λ$. In all models, DM softens the equation of state, systematically reducing $M_{\rm max}$, the radius $R_{1.4}$ (at $1.4M_{\odot}$), and the tidal deformability $Λ_{1.4}$ (at $1.4M_{\odot}$) as $k_F^{\rm DM}$ increases. Consequently, the $2 M_\odot$ pulsar limit and NICER data place a model-dependent upper limit on the DM content, while the GW170817 tidal bound requires a minimal DM content for the stiffest functional. Using a recent Bayesian inference of the DDRMF equation of state as the nucleonic reference band, we evaluate if this DM imprint can be distinguished from nucleonic uncertainties using only measureable quantities. Analyzing the tidal deformability $Λ$ and mass-radius slope $dR/dM$ at fixed mass, we find that $Λ$ is a sharp discriminator: at $1.4 M_\odot$ and $k_F^{\rm DM}=0.06$ GeV, the DM-induced reduction of $Λ$ reaches $\simeq 8$ times the nucleonic $1σ$ width (model-independently $7.5$-$7.8σ$). The DM track leaves the nucleonic $1σ$ band for $k_F^{\rm DM}\gtrsim0.03$-$0.04$ GeV, whereas $dR/dM$ becomes diagnostic only for the heavier ($1.8$-$2.0 M_\odot$) branch.
