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.

斯特罗明格和合作者将研究爱因斯坦引力场方程所隐含的无限多的自然对称性，并在上一个资助周期中发现。它们出现在时空的边界，既在无限光的距离处，又靠近快速旋转黑洞的地平线。该理论研究在引力波、引力记忆、事件视界望远镜即将进行的天文观测方面具有潜在的应用。事件视界望远镜是一项利用遍布全球的无线电天线阵列以无与伦比的分辨率对黑洞进行观测的举措。该奖项支持的工作还将解决霍金的黑洞信息悖论，该悖论认为信息在黑洞中可能不守恒。在过去的几年里，该小组发现了三种现象的精确三角等价，这三种现象在各种物理系统中普遍存在，并且已经分别研究了半个多世纪：记忆、软定理和渐近对称。量子场论中的软定理将任何插入“软”（即低能）粒子（例如引力子）的多粒子散射过程与没有软粒子的同一过程联系起来。渐近对称（例如 BMS）是微分同胚它对无穷远的物理数据的作用非常重要。软定理可以导出为与渐近对称性相关的守恒定律的量子矩阵元素。因此它们具有相同的物理内容。三角形的第三个角通过注意到引力记忆效应的布拉金斯基-索恩公式恰好是温伯格软引力子定理的时间傅里叶变换而闭合。三角形有许多重复出现的实例：在量子电动力学、杨-米尔斯理论、引力中，在任意数量的维度上，有或没有超对称性，在一个角上有主导、次主导或次次主导软定理，以及涉及异常的量子三角形。这种对先前充分理解的现象的等价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另外两个角。该项目研究引力三角形。应用于黑洞时，三角形结构表明，即使是经典黑洞也绝非光秃秃的、毫无特征的物体，它也有一个无限的“软毛”头。霍金 1975 年关于信息丢失的论点假定不存在任何此类显着特征，因此该论点无效。这一见解表明该小组将继续对黑洞信息悖论进行新的调查。另一方面，天文观测表明存在近乎极端的克尔黑洞，其视界以接近光速的速度旋转。广义相对论意味着，极端克尔的高红移、近地平线区域（包括最内稳定圆形轨道（ISCO））的动力学受到无限维涌现共形对称性的控制。一般来说，物理系统的对称性可以有效地表征观测数据，并对观测数据产生显着的影响。精密黑洞光谱已经发展到天文学家开始用各种巧妙的方法观察受这种共形对称性控制的时空区域的阶段。拟议的项目将对共形对称性的潜在观测后果进行系统探索，特别是对于已经处于数据收集早期阶段的事件地平线望远镜。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Flat space amplitudes and conformal symmetry of the celestial sphere

天球的平坦空间振幅和共形对称性

DOI：
10.1103/physrevd.96.065026
发表时间：
2017-09
期刊：
Physical Review D
影响因子：
5
作者：
Pasterski, Sabrina;Shao, Shu;Strominger, Andrew
通讯作者：
Strominger, Andrew

Universal interferometric signatures of a black hole’s photon ring

黑洞光子环的通用干涉特征

DOI：
10.1126/sciadv.aaz1310
发表时间：
2019-07-09
期刊：
Science Advances
影响因子：
13.6
作者：
Michael D. Johnson;A. Lupsasca;A. Strominger;G. Wong;Shahar Hadar;D. Kapec;R. Narayan;A. Chael
通讯作者：
A. Chael

Universal polarimetric signatures of the black hole photon ring

黑洞光子环的通用偏振特征