以BSk24为基准的正压流体的符号声速形变：中子星响应
Signed Sound-Speed Deformations of BSk24-Anchored Barotropes: Neutron-Star Response
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中文总结 AI 辅助
该研究以BSk24为基准，通过添加高斯轮廓的声速形变，量化正负局域声速变化对中子星的非线性符号不对称响应，为中子星结构研究提供唯象参考。
中文摘要 AI 辅助
背景：平衡态下的局域声速平方结构会影响中子星的观测值，但修改dP/dε需要热力学自洽的重构并在整个声明域内进行评估。目的：在保持形变几何、准入准则、重构以及固定质量比较协议不变的情况下，量化以统一BSk24为基准的正、负局域声速变化的响应。方法：在c_s²中添加带有五次平滑阶跃激活的高斯轮廓，在重构前会拒绝保留域内任何位置违反P>0或0<c_s²≤1的候选。通过的案例被重构为有效的冷单流体正压流体，并采用托尔曼-奥本海默-沃尔科夫方程和潮汐方程演化。结果：A=0的案例精确再现了未形变的对照组；局域变化会产生持续的压强偏移，重新定位固定质量的中心态，并产生与质量相关的非线性、符号不对称响应；对于A=-0.8和+0.8，在1.4M⊙时ΔΛ/Λ₀分别为(-46.02%,+35.33%)，在2.0M⊙时分别为(-63.52%,+87.17%)；达到的硬化特征在报告端点处仍与核心相连，而软化特征在高质量时成为离核心的壳层。结论：这些基于BSk24的唯象有效正压流体展示了局域声速干预如何通过热力学重构和恒星结构传播；它们并非BSk24的预测，也不是微观组成或相变的证据。
英文摘要
Background: Localized structure in the equilibrium squared sound speed can affect neutron-star observables, but modifying $dP/dε$ requires thermodynamically consistent reconstruction and assessment over the complete declared domain. Purpose: We quantify the response to positive and negative localized sound-speed changes around a unified BSk24 baseline while keeping the deformation geometry, admission criteria, reconstruction, and fixed-mass comparison protocol fixed. Method: A Gaussian profile with quintic smootherstep activation is added to $c_{\rm s}^2$. Proposals violating $P>0$ or $0<c_{\rm s}^2\leq1$ anywhere in the retained domain are rejected before reconstruction. Passing cases are reconstructed as effective cold one-fluid barotropes and evolved with the Tolman-Oppenheimer-Volkoff and tidal equations. Results: The $A=0$ case reproduces the undeformed control exactly. A localized change produces a persistent pressure offset, relocates the fixed-mass central state, and yields a mass-dependent, nonlinear, sign-asymmetric response. For $A=-0.8$ and $+0.8$, respectively, $ΔΛ/Λ_0=(-46.02\%,+35.33\%)$ at $1.4\,M_\odot$ and $(-63.52\%,+87.17\%)$ at $2.0\,M_\odot$. The reached stiffened feature remains core connected at the reporting endpoints, whereas the softened feature becomes an off-center shell at high mass. Conclusions: These phenomenological BSk24-anchored effective barotropes illustrate how a local sound-speed intervention propagates through thermodynamic reconstruction and stellar structure. They are not BSk24 predictions or evidence for a microscopic composition or phase transition.
