RESEARCH / Uniform spectral gap for congruence subgroups of arithmetic lattices in higher-rank Lie groups
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Mathematics#18 in May 2026 Edition

Uniform spectral gap for congruence subgroups of arithmetic lattices in higher-rank Lie groups

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OPENSTEM EDITORIAL SUMMARY

What the research examines

This work establishes a uniform lower bound on the first non-zero Laplace eigenvalue across all congruence covers of arithmetic locally symmetric spaces for higher-rank Lie groups, proving the generalized Selberg conjecture in full generality.

Why it may matter

Crucial for constructing optimal quantum expander graphs, sieving algorithms in number theory, and Ramanujan complexes.

What to examine carefully

Techniques require property (T) of higher-rank algebraic groups and do not generalize directly to rank-1 hyperbolic spaces.

Editorial scope: This is a concise, independently written introduction based on the publisher information, not a full systematic review or independent replication. It must not replace reading the original methods, limitations and conclusions.
STUDENT RESEARCH LENS · ORIGINAL OPENSTEM NOTES

Try a small, reproducible follow-up

Compute eigenvalues of the Hecke operators on congruence quotients of SL(2, Z) using modular symbol algorithms in Sage.

Questions to investigate

  1. How was the sum-product phenomenon in finite simple groups used to control non-elementary random walks?
  2. What quantitative spectral gap lower bound is explicitly derived in terms of the Lie group root system?

These are independently proposed educational investigations, not activities that the original research authors claim to have completed.

Publication & researcher information

JournalInventiones Mathematicae
Published online2026-05-14
Authors (selected)Guillaume Roche, Ananya Sengupta, Stefan Mueller et al.
University / laboratorySorbonne Université
CountryFrance
Corresponding author[email protected] Publicly listed on publisher record

Multi-author research may involve universities in several countries. Unverified institutions and contact addresses are not inferred from authors' names.

Primary sources