English

Invariant derivations and trace bounds

Representation Theory 2025-09-04 v4 Group Theory

Abstract

About 20 years ago, J-P.~Serre announced a bound on the trace of elements of compact Lie groups under the adjoint representation together with related results, provided indications of his proofs, and invited a better proof. This note provides a new, general method for proving such bounds; uses that method to derive Serre's bounds; gives a second proof of Serre's announced results that (we learned) closely follows his original argument; and provides lower bounds for traces of other representations of compact Lie groups and for Brauer characters of finite groups.

Keywords

Cite

@article{arxiv.2312.03101,
  title  = {Invariant derivations and trace bounds},
  author = {Skip Garibaldi and Robert M. Guralnick and Eric M. Rains},
  journal= {arXiv preprint arXiv:2312.03101},
  year   = {2025}
}

Comments

v4 has small improvements to the exposition. v3 re-writes part I, expands other parts of the text, and adds an appendix on finite groups. v2 strengthens the results of part IV

R2 v1 2026-06-28T13:42:12.417Z