Research in Classical and Quantum Gravity

弦理论是一种很有前途的量子引力理论候选者，霍洛维茨将研究弦理论的引力方面。爱因斯坦的广义相对论预言，引力崩塌不可避免地会形成奇点。当这种情况发生时，广义相对论就崩溃了。弦理论将被用来寻找黑洞内部奇点的量子描述，以及使用弦理论来寻找大爆炸的量子描述。相关的问题也将被调查，包括更高维度的黑洞的性质，以及宇宙审查--形成不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它所需的量子力学的概括，特别是霍金的无边界量子态。在一个普遍由量子不确定性支配的宇宙中，日常生活中可预测的准经典领域的起源也将被调查。拟议的活动将结合研究和教学，对研究生和博士后研究人员进行知识和技术方面的培训，这些知识和技术是理解和发现引力物理的核心。空间和时间的性质、宇宙的起源、物质的性质等问题都引起了广大观众的极大兴趣。通过一系列论坛，从公开讲座到参与高中科学教师项目，再到告知媒体记者，作者向更广泛的受众传播了当前研究的方向和结果。通过对适当的机会保持警惕，我们预计未来将继续这一努力。提高人们对科学核心问题的认识将使整个社会受益。

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.