Quantum Gravity, Horizons, and Beyond

量子引力、视界及其他

• 批准号: 2309634
• 负责人: Theodore Jacobson
• 金额: $ 55.13万
• 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: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2309634&HistoricalAwards=false
• 关键词: Quantum; Gravity; Horizons; Beyond

The grant will support research projects on several aspects of gravitational physics where curved spacetime plays a key role. One group of topics pertains to the outstanding fundamental problem of understanding the quantum nature of spacetime. Specifically, research will be carried out pursuant to the nature of quantum states of spacetime. Much of this work focuses on the peculiar role of event horizons, since that is thought to be a promising window on the mysteries of quantum gravity. Other work will be directed at probing the validity of Einstein's theory of gravity by exploring the theoretical and observational consequences of certain modifications of that theory, particularly as that affects the behavior of black holes. A different component of the research will address questions about the behavior of magnetized plasma around astrophysical bodies like neutron stars and black holes, taking into account the effects of curved spacetime. This work could contribute to a better understanding of observations of these objects and their surroundings made with radio telescopes. Finally, in collaboration with an experimental atomic quantum fluid research group, research will be directed at exploring and exploiting the analogy between physics of quantum fluids and fields in curved spacetime, such as in the expanding universe. The results of the proposed research will be disseminated through written articles, as well as seminars, conference talks, and colloquia, and will contribute to our understanding of fundamental questions, as well as to observations and experiments in a more interdisciplinary fashion. The PI will provide instruction and mentoring to graduate and undergraduate students, regarding scientific research, writing, and verbal communication. The PI will design and implement instruction in a University of Maryland summer programs for rising 9th graders and for high school girls interested in physics. All of these activities will contribute to technical training and scientific literacy, as well as understanding and appreciation of the insights of physics.The main areas of work concern: 1) path integral methods for computing horizon entropy in quantum gravity ensembles, 2) non-perturbative reducedphase space quantization of a compact domain in 2+1-dimensional gravity, 3) the origin of outgoing black hole modes, 4) analog quantum field theory in a Bose-Einstein condensate, 5) general relativistic treatment of magnetic helicity around black holes and neutron stars, and 6) black hole horizons in Lorentz-violating gravity theories. Under 1), one project will study the relation between the nonperturbative path integral approach and the recent semiclassical analysis using algebraic quantum field theory, and another will interrogate the role of the near-horizon imaginary time evolution method in computing horizon entropy with an otherwise real spacetime path integral. Under 2) the aim is to further understand the operators and states in the algebraic quantization found previously, including their implications for entropy and Hamiltonian (time evolution). One approach to this will be to determine the relation to the alternative, covariant phase space approach, and to the so-called corner symmetry algebra, on which much work has been done by others. Further, we may extend the treatment to allow for conical singularities, handles, or a black hole in the spatial domain. Under 3) an attempt will be made to improve understanding of the relation between gravitational anomalies and Hawking radiation, and its connection to the puzzle of the origin of the outgoing black hole modes. Additionally, an attempt will be made to use perturbative quantum gravity to characterize the expected quenching of correlations between points, one of which is near a horizon. Projects under 4) will design and interpret analog quantum field theory measurements of the quantized phonon field, working together with the Maryland Bose-Einstein condensate group. Projects under 5) will formulate the general relativistic theory of energy minimization at fixed magnetic helicity in ideal plasmas, as well as of relative helicity in domains like black holes and neutron stars with boundaries allowing for helicity injection. Projects under 6) will probe the nature of black hole horizons with non-stationary horizon generators, to better understand how the horizon structure and the possibility of its curvature singularities in the infinite past or future.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该赠款将支持有关重力物理学几个方面的研究项目，其中弯曲的时空起着关键作用。一组主题与理解时空的量子性质的杰出基本问题有关。具体而言，将根据时空的量子状态进行研究。这项工作的大部分都集中在事件视野的特殊作用上，因为这被认为是量子重力奥秘的一个有前途的窗口。其他工作将用于探索爱因斯坦重力理论的有效性，通过探索该理论某些修饰的理论和观察性后果，特别是因为影响黑洞的行为。该研究的另一个组成部分将解决有关弯曲时空的影响的天体物理周围磁化等离子体（如中子星和黑洞）的行为的问题。这项工作可能有助于更好地理解这些物体及其周围环境的观察。最后，与实验原子量子流体研究小组合作，研究将旨在探索和利用弯曲时空中量子流体和田间物理学之间的类比，例如在扩展的宇宙中。拟议的研究的结果将通过书面文章以及研讨会，会议谈判和校长来传播，并将以更跨学科的方式对我们对基本问题以及对基本问题的理解以及对的识别和实验的贡献。 PI将向研究生和本科生提供有关科学研究，写作和口头交流的指导和指导。 PI将在马里兰大学的夏季计划中设计和实施指导，适用于上升的9年级学生和对物理感兴趣的高中女生。所有这些活动都将有助于技术培训和科学素养，以及对物理学见解的理解和欣赏。工作的主要领域关注：1）计算量子重力集合中计算地平线熵的路径积分方法，2）非扰动性降低量量的非扰动降低量量的非扰动量化量的量子量的量子量，以外1倍量的量子量，3倍的黑色孔，3）黑色孔的原点，3）黑色孔的原点，3）近距离范围，3）4）范围的原始范围，3）4）。 Bose-Einstein冷凝物，5）对黑洞和中子星周围的磁性螺旋性的一般相对论处理，以及6）洛伦兹侵入性重力理论中的黑洞地平线。在1）下，一个项目将研究非扰动路径积分方法与使用代数量子场理论的最新半经典分析之间的关系，而另一个项目将询问近摩尼子假想时间演变方法在计算型地平线熵中的作用，并具有原本真实的空中空间时间积分。 2）目的是进一步了解以前发现的代数量化中的运营商和州，包括它们对熵和汉密尔顿（时间进化）的影响。一种方法是确定与替代性的协变相空间方法的关系，以及与所谓的角落对称代数的关系，而其他人在上面做了很多工作。此外，我们可以扩展处理，以允许空间域中的圆锥形奇异性，手柄或黑洞。在3下）将尝试提高对重力异常和鹰辐射之间关系的理解，以及它与即将到来的黑洞模式起源难题的联系。此外，将尝试使用扰动量子重力来表征点之间相关性的预期淬灭，其中之一是近地平线。项目4）将设计和解释量化声子场的模拟量子场理论测量，并与马里兰州玻色的凝结物组合作。 5）项目将在理想的等离子体中制定固定磁性螺旋性的能量最小化的一般相对论理论，以及在黑洞和中子恒星等域中的相对螺旋性，具有边界，允许螺旋注射。 6）项目将通过非平稳地平线发电机探测黑洞地平线的性质，以更好地理解地平线结构以及其在无限的过去或未来中的曲率奇异性的可能性。这项奖项反映了NSF的法定任务，并通过使用该基金会的知识分子功能和广泛的影响来评估NSF的法定任务，并被认为是值得的。