Gravitation and Black Holes: From Magnetospheres to Firewalls

引力和黑洞：从磁层到防火墙

• 批准号: 1407744
• 负责人: Theodore Jacobson
• 金额: $ 65.14万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1407744&HistoricalAwards=false
• 关键词: Gravitation; Black; Holes; Magnetospheres; Firewalls

This research is directed at developing an improved understanding in three different areas of gravitational physics: 1) puzzling issues that arise when applying quantum mechanics to black holes, 2) tests of possible deviations from standard relativity theory, 3) theory of strong magnetic fields around astrophysical black holes and in other systems. On the second topic, one project involves calculating the predicted form of gravitational waves from spherical collapsing stars and supernovae in a modified gravity theory. Another is a study of the viability of such a theory in the quantum realm, and a third is to develop alternative but similar approaches to quantum gravity. Topics in the third category include the nature of astrophysical jets, and energy extraction from black holes and stars spinning or moving in a magnetized cloud of charged particles. Also, this work studies the impact of gravity on the generation and properties of twisted magnetic field lines, and the mathematical structure of the basic equations and their simulation on computers. All of these approaches address fundamental questions regarding the structure of the universe. The corresponding results will be disseminated through written articles, as well as seminars, conference talks, colloquia and lecture series. The PI will provide instruction and mentoring to a postdoctoral scholar, as well as graduate and undergraduate students, regarding scientific research, writing, and verbal communication. The PI will seek out opportunities to speak on this topic to audiences ranging across the spectrum from the general public to specialists in gravitational physics.In the quantum gravity realm, one project concerns the black hole information paradox and the possible role of the Wheeler-de Witt equation in resolving it. Specifically, this work studies the redundant encoding of information into the local degrees of freedom described by a wave function satisfying the Wheeler-de Witt equation. Another project involves the relation of black hole entropy to vacuum entanglement and Noether charge. This research will try to determine whether the entropy contribution from non minimal coupling is balanced by a corresponding entanglement entropy change in adiabatic physical processes involving matter crossing black hole horizons. On the Lorentz violating gravity topic, this project studies whether the proposal for a UV complete, "Lifshitz" quantum gravity can pass the stability test, when all the higher derivative terms are taken into account at the non-linear level. We will also examine whether the idea of Lifshitz scaling can be applied in a spacetime with a preferred temporal threading but no preferred spatial foliation. Finally, the magnetosphere topics are will concentrate on the definition, computation and interpretation of magnetic helicity in a general relativistic setting, and in the presence of boundaries such as the surface of a neutron star or the horizon of a black hole. This should be useful in determining the role of helicity injection and conservation, and how it relates to energy minimization, in a general relativistic setting.

这项研究旨在提高对引力物理学三个不同领域的理解：1）将量子力学应用于黑洞时出现的令人困惑的问题，2）标准相对论可能偏差的测试，3）天体物理黑洞周围和其他系统中的强磁场理论。关于第二个主题，一个项目涉及在修正的引力理论中计算来自球形坍缩恒星和超新星的引力波的预测形式。另一个是研究这样一个理论在量子领域的可行性，第三个是发展量子引力的替代但类似的方法。第三类的主题包括天体物理喷射的性质，以及从黑洞和在磁化带电粒子云中旋转或移动的恒星中提取能量。研究了引力对扭曲磁力线的产生和性质的影响，基本方程的数学结构及其计算机模拟。所有这些方法都解决了关于宇宙结构的基本问题。 相应的成果将通过书面文章以及研讨会、会议会谈、座谈会和系列讲座传播。PI将为博士后学者以及研究生和本科生提供关于科学研究，写作和口头交流的指导和指导。PI将寻找机会就这一主题向从普通公众到引力物理学专家的各种观众发表演讲。在量子引力领域，一个项目涉及黑洞信息悖论以及惠勒-德维特方程在解决它方面的可能作用。具体来说，本工作研究了将信息冗余编码到由满足Wheeler-deWitt方程的波函数描述的局部自由度中。另一个项目涉及黑洞熵与真空纠缠和Noether荷的关系。 这项研究将试图确定在涉及物质穿越黑洞视界的绝热物理过程中，非最小耦合的熵贡献是否被相应的纠缠熵变化所平衡。在Lorentz违反引力的问题上，本项目研究了当所有的高阶导数项都在非线性水平上考虑时，UV完全的“Lifshitz”量子引力的提议是否可以通过稳定性检验。我们还将研究Lifshitz标度的思想是否可以应用于具有优先时间线程但没有优先空间叶理的时空。最后，磁层专题将集中在广义相对论背景下，以及在中子星星表面或黑洞视界等边界存在的情况下，磁螺旋度的定义、计算和解释。这应该是有用的，在确定螺旋度注入和守恒的作用，以及它如何涉及到能量最小化，在广义相对论设置。