English

Representation theory of finite groups through (basic) algebraic geometry

Representation Theory 2024-11-05 v5 Algebraic Geometry Combinatorics

Abstract

We introduce a new approach to representation theory of finite groups that uses some basic algebraic geometry and allows to do all the theory without using characters. With this approach, to any finite group GG we associate a finite number of points and show that any field containing the coordinates of those points works fine as the ground field for the representations of GG. We apply this point of view to the symmetric group SdS_d, finding easy equations for the different symmetries of functions in dd variables. As a byproduct, we give an easy proof of a recent result by Tocino that states that the hyperdeterminant of a dd-dimensional matrix is zero for all but two types of symmetry.

Keywords

Cite

@article{arxiv.2009.02774,
  title  = {Representation theory of finite groups through (basic) algebraic geometry},
  author = {Enrique Arrondo},
  journal= {arXiv preprint arXiv:2009.02774},
  year   = {2024}
}

Comments

Added a new proof of Lemma 1.10, not needing algebraic geometry, but just elementary linear algebra, as kindly suggested by Hiraku Atobe. Comments still welcome

R2 v1 2026-06-23T18:20:46.787Z