English

Strong asymptotic freeness of Haar unitaries in quasi-exponential dimensional representations

Probability 2025-03-03 v2 Group Theory Operator Algebras Representation Theory

Abstract

We prove almost sure strong asymptotic freeness of i.i.d. random unitaries with the following law: sample a Haar unitary matrix of dimension nn and then send this unitary into an irreducible representation of U(n)U(n). The strong convergence holds as long as the irreducible representation arises from a pair of partitions of total size at most n142εn^{\frac{1}{42}-\varepsilon} and is uniform in this regime. Previously this was known for partitions of total size up to logn/loglogn\asymp\log n/\log\log n by a result of Bordenave and Collins.

Keywords

Cite

@article{arxiv.2409.03626,
  title  = {Strong asymptotic freeness of Haar unitaries in quasi-exponential dimensional representations},
  author = {Michael Magee and Mikael de la Salle},
  journal= {arXiv preprint arXiv:2409.03626},
  year   = {2025}
}

Comments

54 pages; v2: improvement in the exposition and correction in the exponents