English

On nonnegative invariant quartics in type A

Algebraic Geometry 2024-02-07 v1

Abstract

The equivariant nonnegativity versus sums of squares question has been solved for any infinite series of essential reflection groups but type A. As a first step to a classification, we analyse AnA_n-invariant quartics. We prove that the cones of invariant sums of squares and nonnegative forms are equal if and only if the number of variables is at most 3 or odd.

Keywords

Cite

@article{arxiv.2402.03722,
  title  = {On nonnegative invariant quartics in type A},
  author = {Sebastian Debus and Charu Goel and Salma Kuhlmann and Cordian Riener},
  journal= {arXiv preprint arXiv:2402.03722},
  year   = {2024}
}
R2 v1 2026-06-28T14:39:42.064Z