Applications of string theory

弦理论是一个解决目前理论物理学不同分支之间存在的许多概念冲突的方案。该理论试图在一个统一的框架内描述我们周围的所有自然现象。这个框架应该描述基本粒子的物理学（目前粒子物理学的标准模型描述得非常成功），以及引力物理学（爱因斯坦广义相对论描述），以符合量子力学基本假设的方式。过去几年来，我们对理论逻辑结构的理解有了迅速发展。提出的研究旨在扩展这些知识并将其应用于大量物理问题的研究。许多这样的问题一直困扰着以前试图解释引力并将其与基础物理学的其他部分统一起来的努力。因此，这些问题应该成为衡量弦理论能否成功实现其宏伟目标的标准。理解与量子引力相关的难题应该用来更好地把握引力在异常情况下的行为。早期宇宙学就是这样一个竞技场，在那里应用弦理论将有希望产生一幅物理学的新图景。这也是最有希望对该理论进行真正检验的背景，即实验性检验。宇宙学已经成为一门非常精确的实验科学，弦理论的印记可能就在我们周围，等待我们变得足够聪明去破译它们！

String theory is a proposed solution to the many conceptual conflicts existing currently between differentbranches of theoretical physics. The theory attempts to describe all natural phenomena around us in one unifiedframework. This framework should then describe the physics of elementary particles(currently described verysuccessfully by the standard model of particle physics), as well as gravitational physics (described by Einsteintheory of general relativity), in a manner consistent with the basic postulates of quantum mechanics.The last few years have seen a rapid development in our understanding of the logical structure of the theory.The research proposed is aimed at extending this knowledge and applying it to the study of a vast array ofphysical questions. Many such questions have plagued previous attempts to quantize gravity and to unify itwith the rest of fundamental physics. As such, these questions should serve as as yardstick for the success ofstring theory in its ambitious goals.Understanding the puzzles related to quantum gravity should be used to get a better grasp of the behavior ofgravity in unusual circumstances. One such arena is that of early universe cosmology, where applying stringtheory will hopefully result in a qualitatively new picture of the physics. This is also the context most hopeful for a true test of the theory, namely an experimental one. Cosmology has become a very precise experimental science, and imprints of string theory may be all around us, waiting for us to become smart enough to decipher them!