论文标题
评估中子星星合并中的近似风味不稳定性指标
Evaluating Approximate Flavor Instability Metrics in Neutron Star Mergers
论文作者
论文摘要
由于中微子快速风味不稳定性，中微子可以迅速改变核心爆发超新星和中子星的核心偏斜区域的风味。如果风味转化的量很大，FFI可能会显着影响超新星的爆炸方式，以及超新星和合并如何用沉重的元素丰富整个宇宙。由于许多最先进的超新星和合并模拟依赖于基于辐射场角矩的中微子传输算法，因此有不完整的信息来确定分布是否不稳定FFI不稳定。在这项工作中，我们测试了文献中几种基于力矩的不稳定性测试的性能。我们在3D中子星级合并模拟的快照上执行与时间无关的一般相对论中微子转运，以生成合理的中微子分布，并检查这些标准中的每个标准都能正确预测不稳定的位置。此外，我们还提供了一种新的``最大熵''不稳定性测试，该测试更为复杂，但对ELN交叉宽度和深度的估计更加详细（尽管仍然近似）。我们发现，这种最大的熵测试和谐振轨迹测试在预测该快照中的不稳定性方面特别准确，尽管所有测试都可以预测不稳定的不稳定，而在很可能是显着的风味转化的情况下。
Neutrinos can rapidly change flavor in the inner dense regions of core-collapse supernovae and neutron star mergers due to the neutrino fast flavor instability. If the amount of flavor transformation is significant, the FFI could significantly affect how supernovae explode and how supernovae and mergers enrich the universe with heavy elements. Since many state of the art supernova and merger simulations rely on neutrino transport algorithms based on angular moments of the radiation field, there is incomplete information with which to determine if the distributions are unstable to the FFI. In this work we test the performance of several proposed moment-based instability tests in the literature. We perform time-independent general relativistic neutrino transport on a snapshot of a 3D neutron star merger simulation to generate reasonable neutrino distributions and check where each of these criteria correctly predict instability. In addition, we offer a new ``maximum entropy'' instability test that is somewhat more complex, but offers more detailed (though still approximate) estimates of ELN crossing width and depth. We find that this maximum entropy test and the resonant trajectory test are particularly accurate at predicting instability in this snapshot, though all tests predict instability where significant flavor transformation is most likely.
