English

Fourier Coefficients for Degenerate Eisenstein Series and the Descending Decomposition

Representation Theory 2020-04-28 v1 Combinatorics Number Theory

Abstract

We determine the unipotent orbits attached to degenerate Eisenstein series on general linear groups. This confirms a conjecture of David Ginzburg. This also shows that any unipotent orbit of general linear groups does occur as the unipotent orbit attached to a specific automorphic representation. The key ingredient is a root-theoretic result. To prove it, we introduce the notion of the descending decomposition, which expresses every Weyl group element as a product of simple reflections in a certain way. It is suitable for induction and allows us to translate the question into a combinatorial statement.

Keywords

Cite

@article{arxiv.1606.08872,
  title  = {Fourier Coefficients for Degenerate Eisenstein Series and the Descending Decomposition},
  author = {Yuanqing Cai},
  journal= {arXiv preprint arXiv:1606.08872},
  year   = {2020}
}