Applications of Topology to Arithmetic and Algebraic Geometry

这个项目将曲线的模空间的拓扑知识应用于算术和代数几何问题。该项目的三个主要焦点是：（1）理解普遍的椭圆动机。这些是与所有椭圆曲线相关的动机（混合霍奇结构，伽罗瓦表示等）。椭圆动机有助于解释，例如，为什么经典的模形式将关系强加于多个zeta函数的特殊值。他们还帮助PI理解与椭圆曲线和模形式相关的伽罗瓦表示的扩展之间的关系。(2)理解无限域上光滑射影曲线的有理点。这是在主要调查员先前工作的基础上进行的。他和他的合作者正在将其扩展到积极特征的领域。(3)使用某些模空间的基本群的知识（如映射类群）来研究代数几何中的基本问题。PI研究的一个这样的问题是是否每一条光滑的射影曲线都被一条光滑的平面曲线支配。拓扑学是研究“拓扑空间”的形状。一组代数方程的解的集合形成了一个拓扑空间。它的形状通常对方程的解的集合施加很大的控制，特别是当解需要是整数或整数的比率（称为“有理数”）时。PI与他的合作者和学生一起，利用他对一些非常特殊（和复杂）的空间（称为模空间）的形状的知识，帮助理解一些非常一般的代数方程组的有理和整数解。代数曲线及其有理点一直是数学家们研究的对象。他们的研究虽然深奥，但现在在现代密码学中起着重要的作用。

This project is applying knowledge of the topology of moduli spaces of curves to problems in arithmetic and algebraic geometry. The three main foci of the project are to:(1) understand universal elliptic motives. These are motives (mixed Hodge structures, Galois representations, etc) associated to all elliptic curves. Elliptic motives are helping to explain, for example, why classical modular forms impose relations on special values of multiple zeta functions. They are also helping the PI to understand relations between extensions of Galois representations associated with elliptic curves and modular forms.(2) understand rational points of smooth projective curves over finitely generated infinite fields. This builds on earlier work of the principal investigator. He and his collaborators are extending it to fields of positive characteristic.(3) use knowledge of fundamental groups of certain moduli spaces (such as mapping class groups) to investigate fundamental questions in algebraic geometry. One such question being studied by the PI is whether every smooth projective curve is dominated by a smooth plane curve.Topology is the study of the shape of "topological spaces". The set of solutions of a set of algebraic equations forms a topological space.Its shape often exerts a lot of control over the set of solutions of the equations, especially when the solutions are required to be whole numbers, or ratios of whole numbers (known as "rational numbers"). The PI, with his collaborators and students, is using his knowledge of the shapes of some very special (and complicated) spaces, called moduli spaces, to help understand rational and integer solutions to some very general systems of algebraic equations. Algebraic curves and their rational points have long been studied by mathematicians. Their study, although esoteric, now plays an important role in modern cryptography.This project is jointly funded by the Topology Program and the Algebra and Number Theory Program.