English

A quantitative version of the non-abelian idempotent theorem

Classical Analysis and ODEs 2012-12-04 v2 Combinatorics

Abstract

Suppose that G is a finite group and A is a subset of G such that 1_A has algebra norm at most M. Then 1_A is a plus/minus sum of at most L cosets of subgroups of G, and L can be taken to be triply tower in O(M). This is a quantitative version of the non-abelian idempotent theorem.

Keywords

Cite

@article{arxiv.0912.0308,
  title  = {A quantitative version of the non-abelian idempotent theorem},
  author = {Tom Sanders},
  journal= {arXiv preprint arXiv:0912.0308},
  year   = {2012}
}

Comments

82 pp. Changed the title from `Indicator functions in the Fourier-Eymard algebra'. Corrected the proof of Lemma 19.1. Expanded the introduction. Corrected typos

R2 v1 2026-06-21T14:18:29.074Z