English

A Haagerup inequality through the use of orthogonal polynomials

Operator Algebras 2025-10-21 v1

Abstract

In this paper we prove that the Haagerup inequality for non-homogeneous polynomials in free semicircular variables of degree nn is optimal with a constant of order n3/2n^{3/2}. We also show an operator valued Haagerup inequality which improves on existing results. Our main tool to do so are free Chebyshev polynomials also known as 00-Hermite polynomials.

Keywords

Cite

@article{arxiv.2510.16667,
  title  = {A Haagerup inequality through the use of orthogonal polynomials},
  author = {Félix Parraud},
  journal= {arXiv preprint arXiv:2510.16667},
  year   = {2025}
}