general relativistic astrophysics - Multi-messengaer astrophysics of gravitational wave sources

LIGO/VIRGO对紧凑天体发射的引力波的直接探测不仅证实了广义相对论的一个关键预测，而且为与引力波源相关的极端环境下的物理学和天体物理学的研究开辟了新的机会。GW170817的电磁对应物的发现，是由中子星合并引起的，坚定地确立了时域多信使天文学的可行性和重要性。GW源是非均匀的物体类别，并且GW的频率/波长由发射器的线性尺寸决定。因此，产生多信使信号的相关物理过程在打破广义相对论模型中标度退化的系统中会有很大的不同。例如，一颗中子星在合并之前是如何与另一颗中子星相互作用的，以及合并过程后产生的黑洞如何与富含中子的残余碎片相互作用？当两颗中子星融合形成黑洞时，富含中子的物质的物理状态是什么？当中子星在螺旋过程中变成大质量黑洞时，这个过程产生的电磁辐射是如何改变的？中子星的轨道动力学如何受到强引力相互作用和自旋-自旋和自旋-曲率相互作用的影响？学生将从中选择一个或两个相关的组织。目标是建立一个理论框架来模拟多信使签名，并做出可以通过当前和未来工具进行测试的预测。这是一个现象学和理论项目，重点是引力波的天体物理方面的研究。

The direct LIGO/VIRGO detection of gravitational waves (GW) emitted by compact astrophysical objects not only confirmed a key prediction of general relativity but also opens up new opportunities for the investigation of physics and astrophysical in the extreme environments associated with the GW sources. The discovery of the electromagnetic counterpart of GW170817, which was due to a neutron-stars merger firmly established the viability and the importance of time-domain multi-messenger astronomy. GW sources are inhomogeneous classes of objects, and the frequencies/wavelengths of the GW are determined by the linear size of the emitter. As such, the associated physics processes that give rise to the multi-messenger signals would vary substantially among the systems which break the degeneracy of scaling in generalrelativity models. For instance, how does a neutron star interact with another neutron star before they undergo merging and how would the resulting black hole interact with the neutron-rich remnant debris after the merging process? What is the physical condition of the neutron-rich matter when two neutron stars are being fused into forming a black hole? How does the electromagnetic radiation that the process generatedis modified when a neutron star is in an in-spiral process into a massive black hole? How would the orbital dynamic of the neutron star be affected by the strong gravitational interaction and the spin-spin and spin-curvature interactions? The student will select one or two related tissues among those mentioned. The objectives are to develop a theoretical framework to model the multi-messenger signatures and to makepredictions that can be tested by current and future instruments. It is phenomenological and theoretical project, emphasis on the astrophysical aspects of gravitational wave research.