Eric Urban: Eisenstein Congruences and Euler Systems

Eric Urban: Eisenstein Congruences and Euler Systems

Formal & Physical Sciences Mathematics PBMathematicsPBHNumber theory
🎙 Eric Urban 👥 56K 📅 June 25, 2026 ⏱ 66 min 👁 206 📄 conference talk 🧭 2026-08-13
Available in: English (current) Français

Keywords

Eisenstein idealEuler systemsGalois representationsp-adic familiesIwasawa theory

Summary

Eric Urban presents his recent work on constructing Euler systems via Eisenstein congruences. He begins by recalling the classical construction for GL2, using ordinary and critical Eisenstein series to obtain cohomology classes. He then explains how to generalize this to GSp(2g) using the doubling method and p-adic families of Eisenstein series. The main result is the construction of an Euler system for a Galois representation attached to a cuspidal automorphic representation of GSp(2g) under certain assumptions. He discusses the role of the full Hida–Hecke algebra and the period map in making the construction integral and canonical. He also addresses the case g=1, recovering a known Euler system for a character. The talk concludes with technical details on the use of the universal deformation ring and the construction of cohomology classes in the appropriate modules.

134 words

Critical Evaluation

Value of the Information & Strength of the Argument

The talk presents original research with high mathematical value, offering a new method to construct Euler systems via Eisenstein congruences. The argumentation is rigorous, relying on deep results from p-adic Hodge theory, automorphic forms, and Iwasawa theory. The speaker carefully explains the steps and addresses questions from the audience, clarifying technical points. The approach is innovative and has potential applications to the Bloch–Kato conjecture and the main conjecture of Iwasawa theory.

Scientific Rigor, Source Quality, Title Accuracy

The talk is scientifically rigorous, with the speaker referencing his own work and that of others (e.g., the work of Wiles and others on congruences). The sources are not explicitly listed in the description, but the talk is part of a conference at the Simons Foundation, which adds credibility. The title accurately reflects the content, focusing on Eisenstein congruences and Euler systems. The presentation is technical and assumes a high level of expertise, but it is coherent and well-structured.

165 words

Title / Content Match

The title accurately reflects the content, which focuses on Eisenstein congruences and their application to constructing Euler systems.

Quality & Reliability

8/10

Talk by a leading expert in the field, presenting original research with technical depth. The content is highly specialized and assumes advanced knowledge. The presentation is rigorous, but the transcription is imperfect and some details are incomplete.

Key Moments

Cited Sources

Concurring Sources

Contribution & Novelties

The talk presents a novel method to construct Euler systems via Eisenstein congruences, extending previous work to higher rank groups. The approach uses p-adic families of Eisenstein series and the doubling method, and addresses integrality issues via the full Hida–Hecke algebra. This has potential applications to the Bloch–Kato conjecture and the main conjecture of Iwasawa theory.

Pour aller plus loin :

  • Eisenstein ideal — Background on the Eisenstein ideal and its role in number theory.
  • Euler system — Definition and applications of Euler systems in Iwasawa theory.
  • Iwasawa theory — Overview of Iwasawa theory, which is central to the talk.
  • p-adic L-functions — Relevant to the interpolation of L-values discussed in the talk.

113 words

Radar Profile

The radar profile shows very high scores in technical level and information quality, indicating a highly specialized and rigorous presentation. The quantity of information is also high, but the accessibility is limited due to the advanced nature of the content.

Reliability 9/10