International Research Fellowship Program: Nongeometric Compactifications and String Theory

0402111威廉姆斯国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。 该计划的奖项提供了合作研究的机会，并利用独特或互补的设施，专业知识和国外的实验条件。该奖项将支持博士布鲁克P.威廉姆斯二十二个月的研究奖学金与博士扬德布尔在阿姆斯特丹大学在荷兰。沿着通常的几何对称性目前在更传统的量子场论，弦理论有额外的对称性，它们本质上是“弦”的。 在Hellerman，McGreevy和威廉姆斯（2002）的工作之后，本研究利用这些弦对称的存在性来寻找一类新的“非几何”紧化。 这些对称性允许人们施加边界条件，（描述内部流形的大小和形状的参数）在B场（耦合到基本弦的“电磁”势）和几何被同等对待。B场和几何不能彼此分离;正是在这个意义上，这些紧化被认为是"非几何的“。理解这些紧化是理解量子水平上的什么结构可以取代我们的经典几何概念并成为弦现象学潜在的重要领域的关键一步。

0402111WilliamsThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-two-month research fellowship by Dr. Brookie P. Williams to work with Dr. Jan de Boer at the University of Amsterdam in the Netherlands.Along with the usual geometric symmetries present in more traditional quantum field theories, string theory has additional symmetries which are inherently ``stringy" in nature. Following the work of Hellerman, McGreevy and Williams (2002), this research exploits the existence of these stringy symmetries to find a new class of ``nongeometric'' compactifications. These symmetries allow one to impose boundary conditions which force the moduli (parameters which describe the size and shape of the internal manifold) to vary over spaces in which the B-field (the ``electromagnetic'' potential which couples to the fundamental string) and the geometry are treated on equal footing.The B-field and geometry cannot be disentangled from one another; it is in this sense that these compactifications are considered to be ``nongeometric''. Understanding these compactifications is a crucial step in understanding what structures at the quantum level may replace our classical notions of geometry and serve as potentially important arenas for string phenomenology.