Midisuperspace Laboratories for Loop Quantum Gravity

对黑洞如何蒸发的研究也许是当今理论物理学中最重要的悬而未决的问题。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，理解物理学理论如何在具有挑战性的体系中组合在一起，导致了对壮观后果的洞察。这方面的一个例子可能是麦克斯韦理解电和磁如何结合在一起导致了无线电波的发现，以及随之而来的他们在我们的社会中引起的转型变化。这类工作的第二个非常重要的目标是形成非常高质量的人力资源。事实证明，在这些学科中受过训练的物理学家在工业和金融领域都很有价值。PI将继续通过国际圈量子引力研讨会和圈量子引力门户网站及其博客为公众开展外联活动。将继续在球对称背景下应用圈量子引力技术，其最终目标是理解黑洞蒸发。其中要考虑的主题是：A）研究弱引力猜想在圈量子引力中的适用性。这个猜想指出，不使引力成为最弱相互作用的理论可能导致裸奇点。圈量子引力消除了奇点，因此可以绕过猜想的负面后果。 B）黑洞蒸发模型，其中霍金辐射通过物质场建模。到目前为止，还没有在圈量子引力的背景下研究这些模型。C）扩展我们以前对圈量子引力中标量场坍缩的临界性的研究，以探索经典理论中奇点附近发生了什么。D）将进一步分析该小组提出的在圈量子引力中处理轴对称时空的方法，以探索在球对称的情况下是否消除了奇异性。（E）Mandeltek在20世纪60年代首次提出的关于引力的可观测公式的研究，该研究在其发展过程中遇到了障碍，最近该小组得以消除。该奖项反映了NSF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.