Mathematical Sciences: Properties of Quantum Invariants in 3-Dimensional Topology

数学科学：三维拓扑中量子不变量的性质

• 批准号: 9704893
• 负责人: Lev Rozansky
• 金额: $ 6.53万
• 依托单位: University of Illinois at Chicago
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 1999-08-05
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9704893&HistoricalAwards=false
• 关键词: Mathematical; Sciences; Properties; Quantum; Invariants

9704893 Rozansky An important development in 3d topology of the last decade was a discovery of "quantum invariants," most notably, the Jones polynomial of links and the Reshetikhin-Turaev (RT) invariant of 3-manifolds. Although these invariants are quite effective in classifying knots and 3-manifolds, their topological nature remains mostly obscure. The purpose of this research is to study the topological origin of quantum invariants by decomposing them into simpler pieces, called "finite type invariants," and trying to explain the nature of these pieces individually. This might be accomplished by using the tools of quantum field theory, in particular, the asymptotic expansion of path integrals through Feynman diagrams. E. Witten has identified the Jones polynomial and RT invariant as certain path integrals taken over the classes of SU(2) connections on a 3-manifold. This approach has already led to a discovery of the Alexander polynomial and Milnor linking numbers inside the Jones polynomial. The simplest "pieces" of the RT invariant were identified (at least, as a conjecture) with the Chern-Simons invariant of flat connections, Reidemeister torsion and SU(2) Casson invariant. One hopes that more complicated topological invariants, such as the Casson invariant of other Lie groups, will be found among other pieces of the RT invariant. A classification of knots is an open topological problem. A knot in topology is a closed rope (i.e., a circle) which is knotted. Can a particular knot be untangled by continuously deforming the rope without cutting it? How can one determine this just by looking at a picture of the knot? This problem may be solved if one finds enough knot invariants. A knot invariant is a number that can be calculated by examining a picture of a knot. The number should not change when a knot is continuously deformed. Thus if a knot invariant takes different values on two knots, then these knots are different, because they cannot be deformed into one another. For a long time the only effective knot invariant was the Alexander polynomial. A lot of new invariants, such as the Jones polynomial, were discovered during the last decade. These invariants are quite effective in distinguishing knots, but their origin is still a mystery, because their topological interpretation is mostly missing. The purpose of this project is to try to fill this gap by using the tools of quantum field theory, such as path integral and Feynman diagrams. The relevance of quantum field theory to low dimensional topology was discovered by E. Witten. He demonstrated that the Jones polynomial comes from a particle theory in which knots appear as space-time trajectories of hypothetical elementary particles. The particles interact with each other in ways that resemble the "real life" particles. This approach has yielded numerous mathematical conjectures that may lead to a better understanding of the topological nature of the Jones polynomial and ultimately to the classification of knots. ***

小行星9704893 在过去十年中，三维拓扑学的一个重要发展是发现了“量子不变量”，最著名的是链接的琼斯多项式和3-流形的Reshetikhin-Turaev（RT）不变量。 虽然这些不变量在纽结和三维流形的分类中非常有效，但它们的拓扑性质仍然很模糊。 本研究的目的是研究量子不变量的拓扑起源，将它们分解为更简单的片段，称为“有限型不变量”，并试图单独解释这些片段的性质。 这可以通过使用量子场论的工具来实现，特别是通过费曼图的路径积分的渐近展开。 E.维滕已经确定琼斯多项式和RT不变量作为在3-流形上的SU（2）联络类上取的某些路径积分。 这种方法已经导致发现了亚历山大多项式和米尔诺尔连接数内的琼斯多项式。 RT不变量的最简单的“部分”被确定为（至少作为一个猜想）平坦连接的陈-西蒙斯不变量、雷德迈斯特挠率和SU（2）卡森不变量。 人们希望能在RT不变量的其他部分中找到更复杂的拓扑不变量，如其他李群的卡森不变量。 纽结的分类是一个开放的拓扑问题。 拓扑学中的结是闭合的绳（即，一个圆），它是打结的。 一个特殊的结可以通过不断地使绳子变形而不切断它来解开吗？ 仅仅通过看绳结的图片，怎么能确定这一点呢？ 这个问题可以解决，如果找到足够的结不变量。 结不变量是可以通过检查结的图片来计算的数字。 当线结连续变形时，编号不应改变。 因此，如果一个结不变量在两个结上取不同的值，那么这些结是不同的，因为它们不能变形成另一个。 在很长一段时间里，唯一有效的纽结不变量是亚历山大多项式。 在过去的十年中，发现了许多新的不变量，如琼斯多项式。 这些不变量在区分纽结方面相当有效，但它们的起源仍然是一个谜，因为它们的拓扑解释大多缺失。 这个项目的目的是试图通过使用量子场论的工具，如路径积分和费曼图来填补这一空白。 量子场论与低维拓扑的关联是由E.维滕。 他证明了琼斯多项式来自于粒子理论，在粒子理论中，节点表现为假设的基本粒子的时空轨迹。 粒子以类似于“真实的生命”粒子的方式相互作用。 这种方法已经产生了许多的数学成果，可能会导致更好地理解琼斯多项式的拓扑性质，并最终分类的结。 ***