English

Group representations that resist random sampling

Combinatorics 2015-08-07 v2 Representation Theory

Abstract

We show that there exists a family of groups GnG_n and nontrivial irreducible representations ρn\rho_n such that, for any constant tt, the average of ρn\rho_n over tt uniformly random elements g1,,gtGng_1, \ldots, g_t \in G_n has operator norm 11 with probability approaching 1 as nn \rightarrow \infty. More quantitatively, we show that there exist families of finite groups for which Ω(loglogG)\Omega(\log \log |G|) random elements are required to bound the norm of a typical representation below 11. This settles a conjecture of A. Wigderson.

Keywords

Cite

@article{arxiv.1405.3636,
  title  = {Group representations that resist random sampling},
  author = {Shachar Lovett and Cristopher Moore and Alexander Russell},
  journal= {arXiv preprint arXiv:1405.3636},
  year   = {2015}
}
R2 v1 2026-06-22T04:14:23.652Z