Core Collapse Supernova Gravitational Wave Signature Predictions Based on 3D Ab Initio Models with Increasing GR Realism

基于增强 GR 真实性的 3D Ab Initio 模型的核心塌陷超新星引力波特征预测

• 批准号: 1505933
• 负责人: Anthony Mezzacappa
• 金额: $ 28.41万
• 依托单位: University of Tennessee Knoxville
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-15 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1505933&HistoricalAwards=false
• 关键词: Core; Collapse; Supernova; Gravitational; Wave

Core Collapse Supernovae (CCSN) are catastrophic events that mark the death of massive stars and these violent explosions are responsible for most of the elements in the Periodic Table. The theory of gravity developed by Newton is not sufficient to describe the extreme densities in the CCSN mechanism. As such, CCSN represent an excellent test bed for Einstein's theory of gravity. This project will advance the description of gravity in current CCSN models, from an essentially Newtonian description with a simple correction accounting for some Einsteinian effects to a far more sophisticated approximation of Einsteinian gravity, thereby improving significantly the realism of future CCSN studies. The new models will be used to make predictions for the emission of gravitational waves, ripples in the fabric of space-time, in core collapse supernovae. Such supernovae are among the three primary sources that will produce gravitational waves detectable by the Laser Interferometric Gravitational Wave Observatory (LIGO). The PI will work closely with members of the LIGO Collaboration to develop new tools for LIGO data analysis. This project will train a graduate student in CCSN theory and gravitational wave astronomy and will provide a research opportunity for an intern in the Fisk-Vanderbilt Ph.D. program.Advanced multi-physics models of core collapse supernovae that include multi-frequency neutrino transport with a complete set of neutrino weak interactions and key relativistic corrections such as gravitational redshift, have implemented to date only an effective self-gravitational potential, which is computed using the Newtonian potential obtained by solving the Poisson equation with a correction to the monopole term. The latter is determined from an integral formulation of the Tolman-Oppenheimer-Volkoff equation using angle-average densities. More realistic CCSN models require more sophisticated treatments of the general relativistic gravity. In this project, the PI and his students will implement the Conformally Flat Approximation in CCSN models. This approximation has been shown to describe well general relativistic gravity in systems without rapid rotation or black hole formation, suitable for most CCSN studies. The new models will be used to compute the emission of gravitational radiation in CCSN models using the weak-field, slow-motion approximation and will provide new gravitational wave data to the gravitational wave astronomy community.

核心坍缩超新星（CCSN）是灾难性的事件，标志着大质量恒星的死亡，这些剧烈的爆炸是元素周期表中大部分元素的来源。牛顿发展的引力理论不足以描述CCSN机制中的极端密度。因此，CCSN为爱因斯坦的引力理论提供了一个极好的测试平台。该项目将推进当前CCSN模型中对重力的描述，从本质上的牛顿描述，并对一些爱因斯坦效应进行简单的修正，到更复杂的爱因斯坦引力近似，从而显著提高未来CCSN研究的现实性。新的模型将用于预测引力波的发射，时空结构中的涟漪，以及核心坍缩超新星。这样的超新星是激光干涉引力波天文台（LIGO）可以探测到的引力波的三个主要来源之一。PI将与LIGO合作组织的成员密切合作，开发LIGO数据分析的新工具。该项目将培养一名CCSN理论和引力波天文学方面的研究生，并为Fisk-Vanderbilt博士项目的实习生提供研究机会。核心坍缩超新星的先进多物理模型，包括多频中微子输运和一整套中微子弱相互作用，以及引力红移等关键相对论修正，迄今为止只实现了有效的自引力势，该自引力势是通过求解带单极项修正的泊松方程得到的牛顿势来计算的。后者由托尔曼-奥本海默-沃尔科夫方程使用角平均密度的积分公式确定。更现实的CCSN模型需要对广义相对论引力进行更复杂的处理。在这个项目中，PI和他的学生将在CCSN模型中实现共形平坦近似。这个近似已经被证明可以很好地描述没有快速旋转或黑洞形成的系统中的广义相对论引力，适用于大多数CCSN研究。这些新模型将用于计算CCSN模型中使用弱场、慢动作近似的引力波辐射，并将为引力波天文学界提供新的引力波数据。