Research in Classical and Quantum Gravity

弦理论的引力方面，一个有希望的量子引力理论的候选者，将由霍洛维茨研究。爱因斯坦的广义相对论预言，奇点不可避免地会在引力坍缩中形成。当这种情况发生时，广义相对论就失效了。弦理论将用于寻找黑洞内部奇点的量子描述，以及使用弦理论在大爆炸时的奇点。相关的问题也将被研究，包括更高维度黑洞的特性，以及宇宙审查——形成没有隐藏在事件视界内的奇点的可能性。哈特尔将研究决定宇宙量子态的原理，以及理解宇宙量子态所需的量子力学的概括，特别强调霍金的无边界量子态。在一般由量子不确定性控制的宇宙中，日常经验的可预测准经典领域的起源也将被研究。拟议的活动将通过对研究生和博士后研究人员的知识和技术的培训，将研究和教学结合起来，这些知识和技术是理解和发现引力物理学的核心。空间和时间的性质、宇宙的起源以及物质的性质等问题引起了广大读者的极大兴趣。通过一系列的论坛，从公开讲座到参与高中科学教师的项目，再到通知媒体记者，作者向更广泛的受众传播了当前研究的方向和结果。通过对适当机会的警惕，我们期望在未来继续这一努力。整个社会将受益于提高对科学中心问题的认识。

Gravitational aspects of string theory, a promising candidate for a quantum theory of gravity, will be investigated by Horowitz. Einstein's general theory of relativity predicts that singularities are inevitably formed in gravitational collapse. When this occurs, general relativity breaks down. String theory will be used to search for the quantum description of the singularities inside black holes and at the big bang using string theory. Related questions that will also be investigated include properties of black holes in higher dimensions, and cosmic censorship -- the possibility of forming singularities not hidden inside event horizons. The principles which determine the quantum state of the universe and the generalizations of quantum mechanics needed to understand it with special emphasis on Hawking's no-boundary quantum state will be investigated by Hartle. The origin of the predictable quasiclassical realm of every day experience in a universe governed generally by quantum uncertainty will also be investigated. The proposed activities will integrate research and teaching by hands on training of graduate students and postdoctoral researchers in the knowledge and techniques that are central to understanding and discovery in gravitational physics. Questions such as the nature of space and time, the origin of the universe, and the nature of matter are of great interest to a wide audience. Through a range of forums from public lectures, to participation in programs for high school science teachers, to informing media reporters, the authors have disseminated the directions and results of current research to this broader audience. By being alert to appropriate opportunities we expect to continue this effort in the future. Society at large will benefit by increasing awareness of central problems in science.