Midisuperspace Laboratories for Loop Quantum Gravity

对黑洞如何蒸发的研究可能是当今理论物理学中最重要的突出问题。它需要理解现代物理学的两大支柱——引力和量子场论——在它们最极端的状态下的行为。在过去，理解物理理论如何在具有挑战性的制度中融合在一起，会带来惊人的结果。麦克斯韦就是一个例子，他理解了电和磁是如何结合在一起的，从而发现了无线电波，并由此给我们的社会带来了翻天覆地的变化。这类工作的第二个非常重要的目标是形成高质量的人力资源。受过这些学科训练的物理学家在工业和金融领域被证明是有价值的。PI将通过国际环量子引力研讨会和环量子引力门户及其公众博客继续开展外展活动。环量子引力技术在球对称环境中的应用将继续，最终目标是理解黑洞蒸发。其中需要考虑的课题有：A)弱引力猜想在环量子引力中的适用性研究。这一猜想表明，不把引力视为最弱相互作用的理论可能会导致裸奇点。圈量子引力消除了奇点，因此可以绕过该猜想的负面后果。B)通过物质场模拟霍金辐射的黑洞蒸发模型。到目前为止，这些模型还没有在圈量子引力的背景下进行研究。C)扩展我们之前对环量子引力中标量场坍缩的临界性的研究，以探索在经典理论中奇点附近会发生什么。D)将进一步分析该小组提出的环量子引力中轴对称时空的处理，以探究在球面对称的情况下奇点是否被消除。E)用可观测量来研究引力公式，这是曼德尔施塔姆在20世纪60年代首先提出的，在发展过程中遇到了一个障碍，最近这些研究小组得以消除了这个障碍。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The study of how black holes evaporate is perhaps the most important outstanding problem in theoretical physics today. It requires understanding the behavior of two of the pillars of modern physics, gravity and quantum field theory, in their most extreme regimes. Understanding how physical theories fit together in challenging regimes has in the past led to insights of spectacular consequences. An example of this could be Maxwell understanding how electricity and magnetism fit together led to the discovery of radio waves, with the ensuing transformational changes they induced in our society. A second very important objective of this type of work is the formation of human resources of very high quality. Physicists trained in these disciplines have proved valuable in industry and in finance. The PI will continue the outreach activities via the International Loop Quantum Gravity Seminar and the Loop Quantum Gravity Portal and its blogs for the general public. The application of techniques of loop quantum gravity in spherically symmetric contexts with the ultimate goal of understanding black hole evaporation will continue. Among the topics to be considered are: A) The study the applicability of the weak gravity conjecture in loop quantum gravity. This conjecture states that theories that do not make gravity the weakest interaction may lead to naked singularities. Loop quantum gravity eliminates singularities and therefore could bypass the negative consequences of the conjecture. B) Models of black hole evaporation in which the Hawking radiation is modeled via matter fields. These models have not been studied up to now in the context of loop quantum gravity. C) Extend our previous study of criticality in the collapse of scalar fields in loop quantum gravity to probe what happens close to where the singularity is in the classical theory. D) The treatment of axisymmetric space-times in loop quantum gravity proposed by the group will be further analyzed to probe if the singularity is eliminated in such cases as it is in spherical symmetry. E) Investigations in the formulation of gravity in terms of observables first proposed by Mandelstam in the 1960’s, which faced an obstacle in its development the groups was able to remove recently.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.