论文标题
相对论$npeμ$的散装粘度在中子星合并中
Bulk Viscosity of Relativistic $npeμ$ Matter in Neutron-Star Mergers
论文作者
论文摘要
我们讨论了由弱交互直接URCA工艺引起的热和密集$npeμ$的散装粘度。我们考虑两个感兴趣的制度：（a）具有$ t \ leq t _ {\ rm tr} $的中微子 - 透明度制度（$ t _ {\ rm tr} \ simeq 5÷10 $ mev是中微子 - 链接温度）; （b）用$ t \ geq t _ {\ rm tr} $的中微子捕获的制度。核物质是用密度依赖性参数化DDME2的相对论密度功能方法建模的。在中微子 - 透明体制中，在温度下达到批量粘度的最大粘度，然后在发生中微子陷阱的较高温度下迅速下降。作为一个天体物理的应用，我们通过中子星星合并的大量粘度来估算密度振荡的阻尼时间尺度，并发现，例如，在振荡频率$ f = 10 $ f = 10 $ kHz下，在温度下$ 4 \ leq t \ leq 7 $ meger可能会影响较高的对象，在温度下，阻尼会非常有效。
We discuss the bulk viscosity of hot and dense $npeμ$ matter arising from weak-interaction direct Urca processes. We consider two regimes of interest: (a) the neutrino-transparent regime with $T\leq T_{\rm tr}$ ($T_{\rm tr}\simeq 5÷10$ MeV is the neutrino-trapping temperature); and (b) the neutrino-trapped regime with $T\geq T_{\rm tr}$. Nuclear matter is modeled in relativistic density functional approach with density-dependent parametrization DDME2. The maximum of the bulk viscosity is achieved at temperatures $T \simeq 5÷6$ MeV in the neutrino-transparent regime, then it drops rapidly at higher temperatures where neutrino-trapping occurs. As an astrophysical application, we estimate the damping timescales of density oscillations by the bulk viscosity in neutron star mergers and find that, e.g., at the oscillation frequency $f=10$ kHz, the damping will be very efficient at temperatures $4\leq T\leq 7$ MeV where the bulk viscosity might affect the evolution of the post-merger object.
