Classical and Quantum Aspects of Black Holes, Horizons and Asymptotic Symmetries

黑洞、视界和渐近对称性的经典和量子方面

基本信息

批准号：
1707938
负责人：
Andrew Strominger
金额：
$ 21万
依托单位：
Harvard University
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2021-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1707938&HistoricalAwards=false
关键词：
Classical Quantum Aspects Black Holes

项目摘要

Strominger and collaborators will investigate the infinitely many symmetries of nature implied by the Einstein equations for the gravitational field and discovered under the last grant cycle. These arise at the boundaries of spacetime, both at infinite light like distances and near the horizon of a rapidly spinning black hole. The theoretical research has potential applications to gravitational waves, gravitational memory, upcoming astronomical observations at the Event Horizon telescope. The Event Horizon telescope is an initiative to create observations of black holes of unparalleled resolution using an array of radio antennas located across the globe. The work supported by this award will also tackle Hawking?s black hole information paradox, which posits that information may not be conserved in a black hole. In the last few years, this group has discovered an exact triangular equivalence of three phenomena which recur ubiquitously across a wide variety of physical systems and have been separately studied for over a half century: memory, soft theorems, and asymptotic symmetries. Soft theorems in quantum field theory relate any multi-particle scattering process with the insertion of a 'soft' (i.e. low-energy) particle such as a graviton to the same process without the soft particle.Asymptotic symmetries (such as BMS) are diffeomorphisms which act nontrivially on the physical data at infinity. The soft theorems can be derived as the quantum matrix elements of the conservation laws associated to the asymptotic symmetries. Hence they have the same physical content. The third corner of the triangle is closed by noting that The Braginsky-Thorne formula for the gravitational memory effect is precisely the Fourier transform in time of the Weinberg soft graviton theorem. There are many recurring instances of the triangle: in QED, Yang-Mills theory, gravity, in any number of dimensions, with or without supersymmetry, with leading, subleading or subsubleading soft theorems in one corner, and quantum triangles involving anomalies. This discovery of the equivalence of previously well-understood phenomena enables us to discover brand new phenomena. Given one corner of the triangle, we now know how to find the other two. This project investigates gravitational triangles. Applied to black holes, the triangular structure was shown to imply that, far from being bald featureless objects, even classical black holes carry an infinite head of 'soft hair'. The absence of any such distinguishing features was presumed in Hawking's 1975 argument for information loss, which is therefore invalidated. This insight suggests new lines of investigation into the black hole information paradox which the group will pursue. In another direction, astronomical observation suggests the existence of near-extreme Kerr black holes whose horizons spin at nearly the speed of light. General relativity implies that the dynamics of the high-redshift, near-horizon region of extreme Kerr, which includes the innermost stable circular orbit (ISCO), is governed by an infinite-dimensional emergent conformal symmetry. Symmetries of physical systems in general may both usefully characterize and have striking consequences for observational data. Precision black hole spectroscopy has advanced to the stage where astronomers are beginning to observe -- with a variety of ingenious methods -- the regions of spacetime governed by this conformal symmetry. The proposed project will undertake a systematic exploration of potential observational consequences of the conformal symmetry, in particular for the Event Horizon telescope which is already in the early stages of data collection.

Strominger和合作者将研究爱因斯坦方程对重力领域所隐含的无限自然对称性，并在最后一个赠款周期中发现。这些都是在时空的边界上出现的，无论是在无限的光线距离和迅速旋转的黑洞的地平线附近。理论研究具有潜在的应用于引力波，重力记忆，即将进行的活动望远镜的天文观测。事件地平线望远镜是一项旨在，使用位于全球的一系列无线电天线来创建无与伦比分辨率的黑洞。该奖项支持的工作还将解决Hawking的Black Hole Information Paradox，其中认为信息可能无法在黑洞中保存。在过去的几年中，该群体发现了三种现象的确切三角形等效性，这些现象在多种物理系统中遍布普遍存在，并已分别研究了半个世纪：记忆，软定理和渐近的对称性。量子场理论中的软定理将任何多粒子散射过程与插入“软”（即低能量）粒子（例如重力）的插入（即没有软粒子）的插入与同一过程（例如BMS）是相同的过程（例如BMS），是在Infinity上无怪异的物理数据的差异性。软定理可以推导为与渐近对称性相关的保护定律的量子矩阵元素。因此，它们具有相同的身体内容。三角形的第三个角是通过指出引力记忆效应的布拉金斯基 - thorne公式恰恰是温伯格软重力定理时间的傅立叶变换。三角形有许多反复出现的实例：在QED中，Yang-Mills理论，重力，任何数量的维度，有或没有超对称性，带有一个角落的领先，转标的或近距离的软定理，以及涉及异常的量子三角形。对以前充分理解的现象的等效性的发现使我们能够发现全新的现象。给定三角形的一个角，我们现在知道如何找到其他两个角落。该项目调查了引力三角。三角形结构适用于黑洞，这表明，远非秃头的物体，即使是古典的黑洞，也带有无限的“软头发”头。霍金（Hawking）1975年的信息丢失论点中假定缺乏任何这种区别特征，因此这是无效的。该见解表明，对小组将追求的黑洞信息悖论进行了新的调查。在另一个方向上，天文观察表明存在近极端的kerr黑洞，其地平面几乎以光速旋转。一般相对性意味着，极端Kerr的高红移，近野体区域的动力学，其中包括最内向的稳定圆形轨道（ISCO），受无限二二维的紧急形式对称性的控制。物理系统的对称性通常可以有效地表征和对观察数据产生显着后果。精确的黑洞光谱已升级到天文学家开始观察到的阶段 - 采用多种巧妙的方法 - 由这种结构对称性控制的时空区域。拟议的项目将对保形对称性的潜在观察后果进行系统的探索，尤其是对于事件的地平线望远镜，该望远镜已经处于数据收集的早期阶段。