致密恒星因暗物质诱导坍缩成黑洞的嬗变时标
Transmutation Timescales for Dark Matter Induced Collapse of Compact Stars into Black Holes
- Manipal Academy of Higher Education（曼加洛尔高等教育部）
- Tata Institute of Fundamental Research（塔塔基础研究所）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本研究推导致密恒星捕获暗物质后嬗变为黑洞的时标解析表达式，更新暗物质粒子质量与散射截面的约束，拓展致密恒星探测的暗物质参数空间。
中文摘要 AI 辅助
致密恒星捕获的超重非对称暗物质（DM）粒子可发生热平衡、自引力作用并坍缩形成内寄生黑洞（EBH），该黑洞后续增长可能将宿主恒星嬗变为黑洞。年老毫秒脉冲星（MSP）和白矮星（WD）的持续存在，对暗物质粒子质量$m_\u03c7$与暗物质-核子散射截面$\u03c3_{\rm n\u03c7}$施加了严格约束。本研究通过求解EBH增长方程，推导了嬗变时标的解析表达式，该表达式一致考虑了恒星物质的邦迪吸积、霍金蒸发以及稳态捕获 regime 中EBH的持续暗物质供给；还纳入了流体动力学描述失效时重子吸积的量子效应，为EBH在粒子与流体 regime 的增长提供了统一处理。针对费米子和玻色子非对称暗物质，采用物理上清晰的坍缩判据，计算了不同暗物质密度环境下典型MSP和WD的EBH嬗变时标。尽管物理要素与此前研究大致相似，本研究通过EBH增长的闭式解析处理及采用的EBH形成时标方案，推导了更新的约束，得到了持续增长所需的更低临界EBH质量和修正后的嬗变时标。要求MSP的嬗变时间超过约1 Gyr、WD的嬗变时间超过约10 Gyr，本研究推导了$m_\u03c7$在$10^6$--$10^{14}$ GeV范围内$\u03c3_{\rm n\u03c7}$的修正约束，并表明初始质量小至约$4\times10^4$ kg的EBH可发生持续增长，拓展了致密恒星探测到的暗物质参数空间区域。
英文摘要
Ultra-heavy asymmetric dark matter (DM) particles captured by compact stars can thermalize, self-gravitate, and collapse to form an endoparasitic black hole (EBH), whose subsequent growth may transmute the host star into a black hole. The continued existence of old millisecond pulsars (MSPs) and white dwarfs (WDs) thus places powerful constraints on the DM particle mass $m_χ$ and the DM-nucleon scattering cross-section $σ_{\rm nχ}$. We derive an analytical expression for the transmutation timescale by solving the EBH growth equation, consistently accounting for Bondi accretion of stellar matter, Hawking evaporation, and sustained DM feeding of the EBH in a steady-state capture regime. We also incorporate quantum effects in baryonic accretion when the hydrodynamic description breaks down, providing a unified treatment of EBH growth across both particle and fluid regimes. Adopting a physically transparent collapse criterion for fermionic and bosonic asymmetric DM, we compute EBH transmutation timescales for representative MSPs and WDs in environments with different DM densities. Although the physical ingredients are broadly similar to previous studies, this work derives updated constraints through a closed-form analytical treatment of EBH growth and an adopted prescription for the EBH formation timescale, yielding a lower critical EBH mass for sustained growth and revised transmutation timescales. Requiring the transmutation time to exceed $\sim 1$ Gyr for MSPs and $\sim 10$ Gyr for WDs, we derive revised constraints on $σ_{\rm nχ}$ over $m_χ\sim 10^{6}$--$10^{14}$ GeV, and show that EBHs with initial masses as small as $\sim 4\times10^{4}$ kg can undergo sustained growth, extending the region of DM parameter space probed by compact stars.
