Topics in Harmonic Analysis on Reductive p-adic Groups

摘要DeBackerThe调查员将继续他的研究到一些主题的调和分析李群在nonarchimedian领域。 第一个目标是建立深度为零的超尖点表示的Murnaghan-Kirillov理论。 在最基本的层次上，默纳汉-基里洛夫理论要求在我们群的超尖点表示和某些共伴轨道积分的傅里叶变换之间建立联系。 由于它们与李型有限群的密切联系，建立这些表示的Murnaghan-Kirillov理论的问题归结为将正则半单轨道积分与广义绿色函数联系起来的问题。 第二个目标是研究稳定性问题。 例如，通过Bruhat-Tits理论以统一的方式明确理解支持在幂零集上的稳定分布空间是有用的。 由于各种齐性结果，这个问题可以通过将正则半单轨道积分与广义绿色函数相关联来解决。李群上的调和分析可以追溯到以下物理问题：描述弹吉他弦的运动。 最终，人们意识到这个问题- 这些行为良好的函数被称为特征标，由此产生的理论被称为调和分析。 到20世纪30年代，数学家们对许多类型的群（例如紧致群或阿贝尔群）的调和分析有了坚定的理解。 在20世纪40年代，相对论物理学的问题使人们开始思考一种更一般的群的调和分析，称为李群。 由巴格曼，Gelfand-Naimark和Harish-Chandra的工作发起，目标是，至于吉他问题，通过研究字符来了解组的功能。 多亏了哈里什-钱德拉，这一目标在很大程度上得以实现。至少部分地基于他对这项工作的理解，朗兰兹在20世纪60年代末被引导制定了他的计划;这个计划是一个巨大的，非凡的知识和思想网络-一种万物的数学理论。例如，哈里斯-泰勒、金-沙希迪和拉弗格的著名著作就提供了它所预期的深刻结果的一个小样本。 由于李群的调和分析在我们理解这一领域的许多问题中起着核心作用，研究人员希望他的研究将有助于未来的进展。

Abstract DeBackerThe investigator will continue his research into a number of topics in harmonic analysis for Lie groups over nonarchimedian fields. The first goal is to establish Murnaghan-Kirillov theory for depth zero supercuspidal representations. At its most basic level, Murnaghan-Kirillov theory asks for a connection between the supercuspidal representations of our group and the Fourier transforms of certain coadjoint orbital integrals. Because of their intimate connection to finite groups of Lie type, the problem of establishing Murnaghan-Kirillov theory for these representations reduces to the problem of associating regular semisimple orbital integrals to generalized Green functions. The second objective is to investigate questions about stability. For example, it would be useful to explicitly understand, in a uniform way via Bruhat-Tits theory, the space of stable distributions supported on the nilpotent set. Thanks to various homogeneity results, this problem can be addressed by associating (as above) regular semisimple orbital integrals to generalized Green functions.Harmonic analysis on Lie groups traces its roots to the following problem from physics: Describe the motion of a plucked guitar string. Eventually, people realized that this problem --- and rather more pure problems like calculating Gauss sums or studying the density of primes in arithmetic progressions --- could be understood by studying certain well-behaved functions on the circle (or other groups). These well-behaved functions are called characters, and the resulting theory is called harmonic analysis. By the 1930s mathematicians had a firm understanding of harmonic analysis on many types of groups (for example, compact or abelian groups). During the 1940s problems from relativistic physics led people to think about harmonic analysis on a more general class of groups, called Lie groups. Initiated by the work of Bargmann, Gelfand--Naimark, and Harish-Chandra, the goal was, as for the guitar problem, to understand functions on the group by studying characters. Thanks mostly to Harish-Chandra this goal was largely realized. Based at least partially on his understanding of this work, in the late 1960s Langlands was led to formulate his program; this program is a vast, remarkable web of conjectures and ideas --- a kind of mathematical theory of everything. For example, the celebrated works of Harris--Taylor, Kim--Shahidi, and Lafforgue provide a small sampling of the deep results it anticipates. As harmonic analysis on Lie groups plays a central role in our understanding of many of the problems in this area, the investigator hopes his research will contribute to future progress.