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University of Illinois at Urbana-Champaign

L-functions and J-spectra

Abstract

dc:description

The relation between Eisenstein series and the J-homomorphism is an important topic in chromatic homotopy theory at height 1. Both sides are related to the special values of the Riemann ζ-function. Number theorists have studied the twistings of the Riemann ζ-functions and Eisenstein series by Dirichlet characters. We first explain congruences of these twisted Eisenstein series of level Γ_1(N) and character χ via the Dieudonné theory of height 1 formal groups and formal A-modules and their finite subgroups. Our approach is based on Katz’s algebro-geometric explanation of p-adic congruences of normalized Eisenstein series E_2k of level 1. The crucial step is to translate the Dirichlet character χ to the Galois descent data of formal A-modules. We further connect congruences of modular forms in the Eisenstein subspace E_k(Γ_1(N),χ) with certain group cohomology involving the Dirichlet character χ. When χ is trivial, this group cohomology is on the E_2-page of a spectral sequence to compute homotopy groups of the K(1)-local sphere, which is the p-completion of the J-spectra. This gives a new explanation of the connection between congruences of E_2k and the image of the stable J-homomorphism in the stable homotopy groups of spheres. Following our analysis of congruences of Eisenstein series, we introduce the Dirichlet J-spectra. The homotopy groups of the Dirichlet J-spectra are related to the special values of the Dirichlet L-functions, and thus to congruences of the twisted Eisenstein series. Moreover, the pattern of these homotopy groups suggests a possible Brown-Comenetz duality of the Dirichlet J-spectra, which resembles the functional equations of the Dirichlet L-functions. In this sense, the Dirichlet J-spectra constructed in this paper are analogs of Dirichlet L-functions in chromatic homotopy theory.

Degree

thesis:*
Name thesis:degree_name
Ph.D.
Level thesis:degree_level
Dissertation
Discipline thesis:degree_discipline
Mathematics
Grantor
University of Illinois at Urbana-Champaign
Year dc:date
2020

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Zhang, Ningchuan
Contributors dc:contributor
  • Ando, Matthew
  • Rezk, Charles
  • Allen, Patrick
  • Stojanoska, Vesna

Subjects

dc:subject × 4

Rights

dc:rights
Statement dc:rights
  • © 2020 by Ningchuan Zhang. All rights reserved.
Language dc:language
en

Identifiers

dc:identifier.*
Handle dc:identifier
http://hdl.handle.net/2142/107887
OAI identifier oai:identifier
oai:www.ideals.illinois.edu:2142/107887

Chain of custody

source
Harvested from
University of Illinois - Urbana-Champaign
Base URL
www.ideals.illinois.edu/oai-pmh
Last updated
2026-07-22
Source record
OAI-PMH GetRecord
citation

Zhang, Ningchuan. L-functions and J-spectra. Dissertation thesis, University of Illinois at Urbana-Champaign, 2020. http://hdl.handle.net/2142/107887