Moduli Spaces: Their Topology and Representations

9803427 Kimura 该项目的目标是在适当的意义上研究曲线模空间及其近亲的“表示环”。这些物体是非平凡拓扑量子场论的严格构造。在曲线模空间的情况下，相应的表示是上同调场论（在 Kontsevich 和 Manin 的意义上），其中最引人注目的例子来自于平滑射影簇的 Gromov-Witten 不变量。研究人员将使用从同伦理论（运算）、代数几何（模空间）和量子场论（费曼图）借用的技术，研究由这些模空间的几何形状产生的此类结构的规范族的性质。最近，数学和理论物理之间的大部分相互作用都围绕着拓扑量子场论，即其可观测量对应于拓扑不变量的量子场论。现在，通过研究格罗莫夫-维滕不变量（与从黎曼曲面到卡勒流形的特定映射空间相关的拓扑不变量），可以严格构造此类理论的非平凡类别。该项目的目的是研究由这些空间的几何学产生的此类理论（及其相关理论）的自然族，并了解它们在几何学建议的自然运算下的属性。成功应该阐明所涉及的数学和物理。 ***

9803427 Kimura This project's goal is to study the "representation ring," in the appropriate sense, of the (homology groups of the) moduli space of curves and its close cousins. Such objects are rigorous constructions of nontrivial topological quantum field theories. In the case of the moduli space of curves, the corresponding representations are cohomological field theories (in the sense of Kontsevich and Manin), the most dramatic examples of which arise from Gromov-Witten invariants of a smooth projective variety. The investigator will study properties of canonical families of such structures arising from the geometry of these moduli spaces, using techniques borrowed from homotopy theory (operads), algebraic geometry (moduli spaces), and quantum field theory (Feynman diagrams). Recently, much of the interaction between mathematics and theoretical physics has revolved about topological quantum field theories, quantum field theories whose observables correspond to topological invariants. A rigorous construction of a nontrivial class of such theories is now possible through the study of Gromov-Witten invariants, topological invariants associated to a certain space of maps from Riemann surfaces into a Kahler manifold. The purpose of this project is to study natural families of such theories (and their relatives) that arise from the geometry of these spaces and to understand their properties under natural operations suggested by the geometry. Success should shed light on both the mathematics and the physics involved. ***