Topics In General Relativity

广义相对论主题

• 批准号: 2207659
• 负责人: Andrew Strominger
• 金额: $ 40.39万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2207659&HistoricalAwards=false
• 关键词: Topics; General; Relativity

The PI's group will push forward at the boundaries of our understanding of both classical and quantum aspects of Einstein's theory of general relativity. The overarching goal is to find a way to describe the gravitational force in terms of quantum mechanics: two fields that have resisted unification for more than a century. The projects described here build on a recent synthesis of long-established techniques developed in the study of soft theorems by particle theorists and in the study by relativists of the asymptotic boundaries of spacetime. This synthesis has ignited a fertile collaboration between physicists in disparate fields from twistor theory to LIGO to string theory. It has led to both new experimental predictions (of novel memory effects) and new concrete insights into spacetime as a quantum theory on the celestial sphere as presciently hypothesized long ago by Newman and Penrose and recently reincarnated as the holographic principle. This enterprise in being driven by an unusually diverse and young group of theoretical physicists.Strominger and collaborators will continue their investigation of the infinitely many nontrivially- acting exact symmetries implied by the Einstein equations. These arise in the deep infrared, both in asymptotically flat spacetimes at null infinity – where they are beautifully and powerfully recast as symmetries of the celestial sphere – and near the horizon of a black hole. This theoretical research has potential implications for gravitational scattering, gravitational memory, upcoming observations at the Event Horizon Telescope (EHT), and the black hole information paradox. They will further develop the powerful and exact triangular equivalence of three ubiquitous phenomena: memory, soft theorems, and asymptotic symmetries. Soft theorems in quantum field theory relate multi-particle scattering process with and without insertions of “soft” (low-energy) particles, such as gravitons. Asymptotic symmetries (such as BMS) are diffeomorphisms that act nontrivially on the physical data at infinity. Soft theorems can be derived as quantum matrix elements of conservation laws associated to the asymptotic symmetries, and are the Fourier transform of the formula for the gravitational memory effect. This research program will develop the many recurring instances of this triangular equivalence in both gravity and gauge theory. They intend to answer the central question of how to enumerate all the non- trivial asymptotic symmetries of general relativity in four asymptotically flat spacetime dimensions. In the past grant cycle, it was shown that gravitational scattering amplitudes can be recast as conformal correlators on the celestial sphere at null infinity, where the powerful tools of two-dimensional conformal field theory can be exploited, bringing a complete understanding of the nontrivial asymptotic symmetries within future reach. Very recently it was that physically observable symmetries organize into the group known as w(1+infinity), a significant step that provides direct connections to twistor theory. Applied to black holes, the triangular structure implies that, far from being bald featureless objects, even classical black holes carry an infinite head of “soft hair.” This insight has led to new lines of inquiry into the black hole information paradox. Observational signatures of various Kerr black hole symmetries will be investigated. General relativity implies that the dynamics of the near-horizon region of extreme Kerr and light rays near the photon ring of any Kerr black hole both display conformal scaling symmetries. Advances in precision black hole imaging are beginning to allow astronomers to observe the regions of spacetime governed by these symmetries, and the project will explore their potential observational consequences.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.

PI的小组将在我们对爱因斯坦一般相对论理论的经典和量子方面的理解的界限上前进。总体目标是找到一种用量子力学来描述重力力量的方法：两个多世纪以来抵抗统一的领域。此处描述的项目是建立在粒子理论家在软定理研究中开发的长期建立技术的最新合成以及相对论的研究中，时空的不对称边界的研究。这种综合引发了从扭转理论到Ligo再到弦理论的不同领域物理学家之间的肥沃合作。它已经导致了新的实验预测（新的记忆效应）和对时空的新型具体见解，这是对天体球体的量子理论，因为纽曼和彭罗斯很久以前就在纽曼和彭罗斯（Newman and Penrose）进行了先见之明，最近作为全息原则重新分配了。这项企业是由一个异常和年轻的理论物理学家群体驱动的。Strominger和合作者将继续研究Einstein方程所隐含的无限无限无效的确切对称性。这些出现在深度红外，均以无限无限的不对称平坦的空间为单位 - 它们像天体球体的对称性一样精美而有力地重塑 - 在黑洞的地平线附近。这项理论研究对重力散射，重力记忆，即将在事件地平线望远镜（EHT）和黑洞信息悖论中的观察结果具有潜在影响。他们将进一步发展三种无处不在现象的强大而精确的三角形等效性：记忆，软定理和不对称的对称性。量子场理论中的软定理与有或没有插入“软”（低能）颗粒（例如重力群）的多粒子散射过程相关联。不对称的对称性（例如BMS）是对无穷大的物理数据非琐碎作用的差异性。软定理可以作为与非对称对称性相关的保护定律的量子矩阵元素得出，并且是引力记忆效应的公式的傅立叶变换。该研究计划将在重力和规程理论中发展该三角等效性的许多反复发生。他们打算回答如何列举四个不对称平坦的时空维度中一般相对性的所有非平凡不对称对称性的中心问题。在过去的赠款周期中，可以证明重力散射放大器可以作为Null Infinity的天体球体上的共形相关器重塑，其中可以探索二维形成式磁场理论的强大工具，从而使对未来未来的非对称不对称的符号符合不太体重的不对称符号。最近，正是在物理上可观察的对称性组织到了称为W（1+Infinity）的组中，这是一个与扭曲理论直接连接的重要步骤。三角形结构适用于黑洞，这意味着，远非秃头的物体，甚至经典的黑洞都带有无限的“柔软的头发”头。这种见解导致了对黑洞信息悖论的新调查。将研究各种Kerr黑洞对称性的观察性特征。一般相对性意味着，kerr的极端kerr和光子环附近的光子射线的近摩尼子区域的动力学都显示出保形尺度对称性。精确的黑洞成像的进步开始使天文学家能够观察由这些对称性支配的时空区域，该项目将探讨其潜在的观察后果。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子和更广泛影响的评估审查审查标准来通过评估来通过评估来支持的。