引力波天文学与理论模型引力波理论建模课件

1、数值相对论与引力波建模的一些新进展Zhoujian Cao (曹周键)Department of Astronomy, BNU2018-5-23第二届引力波天体物理学术研讨会ContentCurrent state of GW theoretical modelFinite element method to NRTheoretical model to eccentric binary systemSummary and prospect引力波探测数据是典型的强噪声、弱信号匹配滤波方法是引力波数据处理的理想方法引力波理论模型可以在既定硬件灵敏度的基础上很好地提高引力波探测的能力GW15122

2、6?13, 5sigma引力波理论模型是波源参数反演的基础双黑洞?双中子星?星体质量、自旋？引力波天文学与理论模型引力波理论建模针对实际的波源天体，求解爱因斯坦方程没有对称性，解析解基本没有希望在极端条件下，近似方法失效数值计算成为主要依赖的方法(数值相对论NR) Current problems faced by NRCurrent NR codesPDE form used by AMSS-NCKUPDE form for FEFE numerical schemeCao, Fu, Ji, and Xia, 2018Shock forms, but really stable!Consis

3、tent to PDE property of non-linearly degenerateMore flexible than PSConvergence behavior better than FD, 4th vs 2ndMore accurate than FD, 2 orders betterComputation cost of NR10 orbits, 256 CPUs, 7daysGW150914: 4 orbits GW151226: 28 orbits3days x 250000 = 2055 years (256CPUs)GW150914State of art for

4、 EOBNRTotal mass: 0MMass ratio: 1q20 GW150914 (1.24), LVT151012 (1.77), GW151226 (1.89), GW170104 (1.61), GW170608 (1.71), GW170814 (1.21)Spin: -1s0.9 GW150914 (0.24), LVT151012 (0.3), GW151226 (0.35), GW170104 (0.42), GW170608 (0.3), GW170814 (0.18)Precession simplified (BCV) GW150914, LVT151012 &

5、GW151226 assume no precession, GW170104, GW170608 & GW170814 gain little constrain on precessione = 0 All announced BBH GW events assumedLSC, ApJ 818, L22 (2016)Binary Black Hole with eccentric orbitPlausible source for LIGOMany sources for LISASEOBNRE modelAssume small eccentricity expansion (c) pa

6、rt effectively more than 4 PN Elip part about 2PNCao & Han, PRD 96, 044028 (2017)Not like adiabatic approximated model, consistent check for e=0 caseCompare to standard answer NRm1:m2 = 1:1e = 0.02m1:m2 = 1:5e = 0.02m1:m2 = 1:1e = 0.2m1:m2 = 1:1000e = 0.3a = 0.9a = 0.5a =-0.5a =-0.9ax-model for eccentric BBHadiabatic approximation modelm1:m2 = 1:1e = 0.3More accurate than adiabatic model for later inspiral and merger初步发展有限元数值相对论算法，希望实现大质量比双星系统和中子星双星系统准确建模描述椭圆轨道双黑洞系统的引力波理论模型SE