English

Constructions of $SU(2)$ and Weyl equivariant maps for all classical groups

Metric Geometry 2021-05-20 v2 Mathematical Physics math.MP

Abstract

If GG is a compact Lie group, TT a maximal torus in GG (with Lie algebras g\mathfrak{g} and t\mathfrak{t} respectively) and WW the corresponding Weyl group, then the Berry-Robbins problem for GG, as formulated by Sir Michael Atiyah and Roger Bielawski, asks whether there exists a continuous SU(2)×WSU(2) \times W equivariant map from the space of regular Cartan triples (an open subset of tR3\mathfrak{t} \otimes \mathbb{R}^3) to G/TG/T, where SU(2)SU(2) acts via a regular Lie group homomorphism SU(2)GSU(2) \to G. This was settled positively by Atiyah and Bielawski, and their maps are even smooth, but they are not explicit. For G=U(n)G=U(n), there exists another construction due to Sir Michael Atiyah and developed further with Paul Sutcliffe, which is explicit, but relies on a linear independence conjecture. The author had previously found a similar type of construction for G=Sp(m)G=Sp(m), also relying on a linear independence conjecture. In this paper, similar constructions are done for SO(2m+1)SO(2m+1) and SO(2m)SO(2m), thus exhausting the list of classical groups.

Keywords

Cite

@article{arxiv.1508.04076,
  title  = {Constructions of $SU(2)$ and Weyl equivariant maps for all classical groups},
  author = {Joseph Malkoun},
  journal= {arXiv preprint arXiv:1508.04076},
  year   = {2021}
}

Comments

16 pages

R2 v1 2026-06-22T10:35:23.260Z